Difference between revisions of "2008 NSF Proposal"

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== The ISU Physics Program==
 
== The ISU Physics Program==
−
The <math>Q_{weak}</math> experiment and the measurement of
 
−
<math>A_1</math> at large<math> x</math> in Jefferson Lab's Hall B represent the
 
−
main components of the principal investigator's physics program.
 
−
Both components are the continuation of the PI's previous work
 
−
in parity violating electron scattering as a Ph.D. student and
 
−
polarized structure functions as a postdoctoral researcher
 
−
based at Jefferson Lab. 
 
−
While the main goal of the <math>Q_{weak}</math> experiment is to measure
 
−
the weak mixing angle <math>\sin^2</math>(<math>\theta_W</math>), the PI has found an
 
−
opportunity to use the same apparatus to measure a new low energy
 
−
fundamental constant known as <math>d_{\Delta}</math> described below.  Such
 
−
an experiment using the <math>Q_{weak}</math> apparatus would require 1 week
 
−
to measure an inelastic parity-violating asymmetry which is an
 
−
order of magnitude larger than the <math>Q_{weak}</math> asymmetry.  While a
 
−
postdoctoral researcher based at Jefferson Lab, the
 
−
PI began developing a program to measure the
 
−
polarized to unpolarized down quark distribution (<math>\frac{\Delta d}{d}</math>) in the nucleon.  The program was recently awarded
 
−
80 days of beam time by Jefferson Lab's PAC 30.  Further details
 
−
of the physics program are given in the subsections below.
 
  
 
===Q_{weak}===
 
===Q_{weak}===
  
−
The <math>Q_{weak}</math> experiment (E05-008) will use parity violating (PV)  
+
The $Q_{weak}$ experiment (E05-008), scheduled for installation in 2010,
 +
will use parity violating (PV)  
 
electron-proton scattering
 
electron-proton scattering
−
at very low momentum transfers <math>(Q^2  \sim  0.03 GeV^2)</math> to measure  
+
at very low momentum transfers $(Q^2  \sim  0.03~ \rm{GeV}^2)$ to measure  
 
the weak mixing  
 
the weak mixing  
−
angle <math>\sin^2(\theta_W)</math>.
+
angle $\sin^2(\theta_W)$.
 
The dominant contribution to the PV  
 
The dominant contribution to the PV  
−
asymmetry measured by <math>Q_{weak}</math> is given by the weak charge of
+
asymmetry measured by $Q_{weak}$ is given by the weak charge of
 
the proton, $Q_W^p = 1-4\sin ^2 \theta _W$,
 
the proton, $Q_W^p = 1-4\sin ^2 \theta _W$,
−
with small corrections at order $Q^4$ from nucleon
+
with small corrections of order $Q^4$ from nucleon
 
electromagnetic form factors.  
 
electromagnetic form factors.  
 
This measurement will be a  
 
This measurement will be a  
 
standard model test  
 
standard model test  
−
of the running of the electroweak coupling constant sin$^2$($\theta_W$).
+
of the running of the electroweak coupling constant, sin$^2$($\theta_W$).
 
Any significant deviation of $\sin ^2 \theta _W$ from the
 
Any significant deviation of $\sin ^2 \theta _W$ from the
 
standard model prediction at  
 
standard model prediction at  
Line 158: Line 140:
 
constraints on possible standard model extensions including new
 
constraints on possible standard model extensions including new
 
physics.   
 
physics.   
−
The experiment is scheduled for installation in the beginning of 2010.
+
A brief
−
The role of the principal investigator in this program is
+
description of the physics behind the $Q_{weak}$ experiment and the
−
described in section~\ref{section:QweakDetector}.  A brief
+
crucial contributions of this proposal to the $Q_{weak}$ experiment are
−
description of the physics behind the Qweak experiment is given below.
+
given below.
−
 
 
−
 
 
  
 
An essential prediction of the Standard Model is the variation of
 
An essential prediction of the Standard Model is the variation of
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gauge couplings. Such tests  
 
gauge couplings. Such tests  
 
have been crucial in establishing QCD as the correct theory of
 
have been crucial in establishing QCD as the correct theory of
−
strong interactions \cite{Hin00},
+
strong interactions~\cite{Hin00}. 
−
and the RGE evolution of the QED coupling has also been
+
The RGE evolution of the QED coupling has also been
−
demonstrated experimentally \cite{TOP97,VEN98,OPAL00,L300}.  
+
demonstrated experimentally~\cite{TOP97,VEN98,OPAL00,L300}.  
 
The gauge coupling of the weak interaction, however, represented at low energies by the weak mixing angle
 
The gauge coupling of the weak interaction, however, represented at low energies by the weak mixing angle
 
$\sin ^2 \theta _W$, has not yet been studied successfully in this respect.
 
$\sin ^2 \theta _W$, has not yet been studied successfully in this respect.
  
−
Shown in Fig.~\ref{fig:newphysics} is the Standard Model prediction in a particular scheme \cite{QweakAp} for $\sin ^2 \theta _W$
+
 
−
versus $Q^2$ along with existing and proposed world data. As seen in this figure, the very
+
 
 +
[[Image:Qweak_s2w_Precision.jpg | 200 px]][[Image:Qweak_s2w_Precision.eps]]
 +
[[Image:A-d_Delta_Prec.xfig.jpg | 200 px]][[Image:A-d_Delta_Prec.xfig.eps]]
 +
 
 +
 
 +
 
 +
\begin{figure}[htbp]
 +
%\vspace{-1in}
 +
\begin{center}
 +
{
 +
\scalebox{0.2} [0.2]{\includegraphics{Graphs/s2w_2004_4_new_2.eps}}
 +
\scalebox{0.25} [0.25]{\includegraphics{Graphs/A_d_Delta_Prec.xfig.eps}}
 +
}
 +
\caption{The dependence of $\sin^2 \theta_W$ as a function of $Q^2$ cast in the MS bar scheme of reference~\cite{Erler}.  The solid line represents the Standard Model prediction. The results from four experiments (APV~\cite{APV}, $Q_W(e)$~\cite{E158}, $\nu$-DIS~\cite{NuTeV}, Z-pole~\cite{Zpole} are shown together with the expected precision from the $Q_{weak}$ experiment (Q$_W(p)$~\cite{Qweak}.  Expected precision of an inelastic asymmetry measured in one week using the Q$_{weak}$ apparatus  compared with the expected asymmetry for several values of the low energy constant $d_{\Delta}$.  The rectangular box indicates both the Q$^2$ bin and the asymmetry uncertainty.}
 +
\label{fig:PVAsym}
 +
\end{center}
 +
\end{figure}
 +
 
 +
Figure~\ref{fig:PVAsym} shows the Standard Model prediction in a particular scheme~\cite{QweakAp} for $\sin ^2 \theta _W$
 +
versus $Q^2$ along with existing and proposed world data. As seen in this Figure, the very
 
precise measurements near the $Z^0$ pole merely set the overall magnitude of the curve; to test
 
precise measurements near the $Z^0$ pole merely set the overall magnitude of the curve; to test
−
its shape one needs precise off-peak measurements. To date, there
+
its shape one needs precise off-peak measurements. Presently, there
 
are only three off-peak measurements  
 
are only three off-peak measurements  
 
of $\sin ^2 \theta _W$ which test the running at a significant
 
of $\sin ^2 \theta _W$ which test the running at a significant
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will be performed with smaller statistical and systematic errors and has a much cleaner
 
will be performed with smaller statistical and systematic errors and has a much cleaner
 
theoretical interpretation than existing low $Q^2$ data. In addition, this measurement resides in the
 
theoretical interpretation than existing low $Q^2$ data. In addition, this measurement resides in the
−
semi-leptonic sector, and is therefore complimentary to experiment E-158 at SLAC, which
+
semi-leptonic sector, and is therefore complimentary to experiment E-158 at SLAC, which
−
has determined $\sin ^2 \theta _W$ from PV $\vec e e$ (Moller) scattering (which
+
resides in the pure leptonic sector and
−
resides in the pure leptonic sector) to roughly a factor of two less precision at low $Q^2$ \cite{E158}.
+
has determined $\sin ^2 \theta _W$ from PV $\vec e e$ (Moller) scattering  
 +
to roughly a factor of two less precision at low $Q^2$~\cite{E158}.
 
The total statistical and systematic error anticipated
 
The total statistical and systematic error anticipated
−
on $Q_W^p$ from these measurements is around 4\% \cite{Qweak},
+
on $Q_W^p$ from these measurements is around 4\%~\cite{Qweak},
 
corresponding to an uncertainty in  
 
corresponding to an uncertainty in  
−
$\sin ^2 \theta _W$ of $\pm$0.0007, and would establish the
+
$\sin ^2 \theta _W$ of $\pm$0.0007.  This would establish the
 
difference in radiative corrections  
 
difference in radiative corrections  
 
between $\sin ^2 \theta _W (Q^2 \approx 0)$ and $\sin ^2 \theta
 
between $\sin ^2 \theta _W (Q^2 \approx 0)$ and $\sin ^2 \theta
Line 207: Line 207:
 
deviation effect.
 
deviation effect.
  
 +
\medskip
 +
\begin{center}
 +
\underline{\sf ISU's role in $Q_{weak}$}
 +
\end{center}
  
 +
PI Forest is currently the work package manager of the Region 1 detector
 +
and front end electronics for $Q_{weak}$. 
 +
The Region 1 tracking system detectors are being assembled and will be
 +
tested by the end of 2008.
 +
This proposal will support the installation of a front end electronics
 +
system from CERN to digitize the analog
 +
output of the detectors. 
 +
PI Forest has been using his startup funds to develop the infrastructure
 +
needed to implement this system in $Q_{weak}$.  A critical milestone in the work plan,
 +
outlined in Table~\ref{table:Timeline}, will be the testing of the integrated tracking system
 +
during the summer of 2009 at JLab in preparation for the installation of the system in early 2010.
 +
Support from this proposal will be used to complete the front end electronics
 +
installation and maintain the Region 1 tracking system during the calibration
 +
phase of the $Q_{weak}$ experiment currently scheduled to begin installation in
 +
JLab's Hall C in early 2010.
  
−
[[Image:Qweak_s2w_Precision.jpg | 200 px]][[Image:Qweak_s2w_Precision.eps]]
+
In addition to providing a key component to the $Q_{weak}$ tracking system, PI Forest has  
−
 
+
also outlined a week long experiment to measure $d_{\Delta}$ using the  
−
\begin{figure}[htbp]
+
$Q_{weak}$ apparatus~\cite{Qweak} to a statistical precision of less than 0.1 ppm as
−
%\vspace{-1in}
+
shown in Figure~\ref{fig:PVAsym}~\cite{LOIdDelta}.
−
\centerline{
+
This low energy constant $d_{\Delta}$ was discovered while evaluating the radiative corrections for the  
−
\scalebox{0.5} [0.5]{\includegraphics{Graphs/s2w_2004_4_new_2.eps}}}
+
PV $N\rightarrow \Delta$ transition~\cite{Zhu012}.  The authors in Ref.~\cite{Zhu012} used Siegert's
−
\caption{The dependence of $\sin^2 \theta_W$ as a function of
+
theorem to show the presence of a non-vanishing PV asymmetry at $Q^2=0$ which is proportional
−
$Q^2$ cast in the MS bar scheme by reference~\cite{Erler}.  The
+
to $d_{\Delta}$.
−
solid line represents the Standard Model prediction.
+
A measurement of the PV asymmetry in the $N\rightarrow \Delta$ transition at the  
−
The results from three experiments
+
photon point, or at very low $Q^2$ would provide a direct measurement of the  
−
(APV~\cite{APV}, $Q_W(e)$~\cite{E158}, $\nu$-DIS~\cite{NuTeV} ,Z-pole~\cite{Zpole} are shown together with the expected
+
low energy constant $d_{\Delta}$.
−
precision from the <math>Q_{weak}</math> experiment (Q$_W(p)$~\cite{Qweak}. }
 
−
\label{fig:newphysics}
 
−
\end{figure}
 
−
 
 
−
 
 
−
\subsubsection{ISU's role in Qweak}
 
−
 
 
−
Dr. Forest is currently the work package manager of the Region 1 Detector and Front End electronics for Qweak.
 
−
The detectors for the region 1 tracking system are being assembled and will be tested by the end of 2008.
 
−
A front end electronics system from CERN has been chosen to digitize the analog output of the detectors.
 
−
Dr. Forest has been using his start up funds to develop the infrastructure needed to implement this system in Qweak.
 
−
The support from this proposal will be used to complete the front end electronics installation and maintain the region 1
 
−
tracking system during the calibration phase of the Qweak experimental currently scheduled to begin installation in JLab's Hall \
 
−
C in early 2010.
 
−
 
 
−
Dr. Forest submitted a Letter of Intent
 
−
(LOI-03-105) to JLab PAC24 which outlined an experiment to measure $d_{\Delta}$,
 
−
shown in Figure~\ref{fig:N2Delta_Asym},  using the  
 
−
$Q_{weak}$ apparatus \cite{Qweak} to statistical precision of $<$ 0.1 ppm in less than a week.
 
−
Interest in inelastic PV physics has been bolstered by the
 
−
discovery of a
 
−
new
 
−
radiative correction for the PV $N\rightarrow
 
−
\Delta$ transition~\cite{Zhu012} resulting in a $Q^2$
 
−
independent asymmetry 
 
−
that does not contribute to elastic PV electron scattering.
 
−
The result is a non-vanishing PV asymmetry at $Q^2 = 0$ .  
 
−
The new correction is the result of a photon coupling to a PV
 
−
hadron vertex and is referred to as the so called ``anapole''
 
−
contribution which has no analog in the elastic channel.
 
−
The authors in Ref.~\cite{Zhu012} use Siegert's
 
−
theorem to show that the
 
−
$Q^2$ independence is the result of a cancellation of the 1/$Q^2$ term
 
−
from the photon propagator and the leading $Q^2$ dependence from
 
−
the anapole term.
 
−
The leading component from the contribution of this transition amplitude
 
−
is proportional to $\omega ~(\omega = E_f -E_i )$
 
−
times the PV electric dipole matrix element and is characterized
 
−
by a low energy constant $d_{\Delta}$. A measurement of the PV
 
−
asymmetry in the $N\rightarrow \Delta$ transition at the photon point,
 
−
or at very low $Q^2$, henceforth called the Siegert contribution,
 
−
would provide a direct measurement of the low
 
−
energy constant $d_{\Delta}$.  
 
  
 
The low energy constant $d_{\Delta}$ is a fundamental constant
 
The low energy constant $d_{\Delta}$ is a fundamental constant
 
which has implications to other long standing physics questions.
 
which has implications to other long standing physics questions.
 
The same PV electric dipole matrix element which results in
 
The same PV electric dipole matrix element which results in
−
$d_{\Delta}$ also drives the asymmetry
+
$d_{\Delta}$ also drives the asymmetry  
 
parameter ($\alpha_{\gamma}$) in radiative hyperon decays, e.g. $\Sigma ^+ \rightarrow p\gamma$.
 
parameter ($\alpha_{\gamma}$) in radiative hyperon decays, e.g. $\Sigma ^+ \rightarrow p\gamma$.
−
Although Hara's theorem \cite{Hara64} predicts that the asymmetry
+
Although Hara's theorem~\cite{Hara64} predicts that the asymmetry
−
parameter ( $\alpha_{\gamma}(\Sigma ^+ \rightarrow p\gamma$)) should
+
parameter ($\alpha_{\gamma}(\Sigma ^+ \rightarrow p\gamma$)) should
 
vanish in the exact SU(3) limit,  the Particle Data
 
vanish in the exact SU(3) limit,  the Particle Data
 
Group~\cite{PDGAlphaSigma} reports a measured value of
 
Group~\cite{PDGAlphaSigma} reports a measured value of
−
$\alpha_{\gamma}(\Sigma ^+ \rightarrow p\gamma) =$-0.72$\pm$ 0.08.
+
$\alpha_{\gamma}(\Sigma ^+ \rightarrow p\gamma) = -$0.72$\pm$ 0.08.
 
While typical SU(3) breaking effects are of order $(m_s - m_u )/1$GeV $\sim$ 15\%,
 
While typical SU(3) breaking effects are of order $(m_s - m_u )/1$GeV $\sim$ 15\%,
 
the above asymmetry parameter is experimentally  
 
the above asymmetry parameter is experimentally  
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to large negative values.  
 
to large negative values.  
 
This same reaction mechanism was also shown to
 
This same reaction mechanism was also shown to
−
simultaneously reproduce the $s-$ and $p-$ wave amplitudes in non-leptonic
+
simultaneously reproduce the $s$- and $p$-wave amplitudes in non-leptonic
 
hyperon decays, which has also been a long standing puzzle in hyperon decay
 
hyperon decays, which has also been a long standing puzzle in hyperon decay
 
physics. If the same underlying dynamics is present in the
 
physics. If the same underlying dynamics is present in the
Line 290: Line 266:
 
$d_{\Delta}$ to be enhanced over its natural scale ($g_{\pi}$ =
 
$d_{\Delta}$ to be enhanced over its natural scale ($g_{\pi}$ =
 
3.8$\times 10^{-8}$, corresponding to the scale of charged
 
3.8$\times 10^{-8}$, corresponding to the scale of charged
−
current hadronic PV effects \cite{Des80,Zhu00}).  
+
current hadronic PV effects~\cite{Des80,Zhu00}).  
−
The authors of Reference\cite{Zhu012} estimate that this enhancement may
+
The authors of Ref.~\cite{Zhu012} estimate that this enhancement may
 
be as large as a factor of 100, corresponding to an asymmetry of
 
be as large as a factor of 100, corresponding to an asymmetry of
−
$\sim$ 4 ppm, comparable to the size of the effects due to the
+
$\sim$ 4 ppm.  This is comparable to the size of the effects due to the
 
axial response and therefore easily measurable. Thus, a
 
axial response and therefore easily measurable. Thus, a
 
measurement of this quantity could provide a window into the
 
measurement of this quantity could provide a window into the
Line 300: Line 276:
  
  
−
[[Image:A-d_Delta_Prec.xfig.jpg | 200 px]][[Image:A-d_Delta_Prec.xfig.eps]]
 
−
 
−
\begin{figure}[htbp]
 
−
\begin{center}{
 
−
%\scalebox{0.4}[0.3]{\rotatebox{-90}{\includegraphics{Graphs/N2Delta_Asym.eps}}}
 
−
\scalebox{0.4} [0.4]{\includegraphics{Graphs/A_d_Delta_Prec.xfig.eps}}
 
−
}
 
−
\caption{Expected precision of the measured asymmetry using the
 
−
Q$_{weak}$ apparatus  compared
 
−
with the expected asymmetry for several values of the low energy
 
−
constant $d_{\Delta}$.  The rectangular box indicates both the
 
−
Q$^2$ bin and the asymmetry uncertainty.}
 
−
\label{fig:N2Delta_Asym}
 
−
\end{center}
 
−
\end{figure}
 
  
 
===Vector Meson and Hyperon Photoproduction with Linearly Polarized Photons===
 
===Vector Meson and Hyperon Photoproduction with Linearly Polarized Photons===
  
−
The probe afforded by a beam of linearly-polarized photons
 
−
allows one to gain access to several observables in photonucleon
 
−
reactions, which otherwise would not be measureable.
 
−
The polarization axis defines a unique direction in space whereby the
 
−
angular distributions of the final-state particles can be uniquely referenced.
 
−
In essence, a beam of linearly-polarized photons cuts down on the glare.
 
−
The polarization axis of the photon beam breaks the
 
−
azimuthal symmetry of the reaction, thereby introducing  an azimuthal
 
−
($\Phi$) dependence in the differential cross section.  This additional
 
−
information on the
 
−
angular dependence opens the door to the measurement of a host of
 
−
observables which are accessible only with a beam of linearly-polarized
 
−
photons; consequently it provides important constraints on the
 
−
nature of the photon-nucleon reaction.  Such polarization observables
 
−
are necessary for extracting the spin/parity of the broadly overlapping
 
−
baryon resonances and measuring such parameters over a large energy range
 
−
with full angular coverage is crucial for disentangling such contributions
 
  
 +
The probe afforded by a beam of linearly-polarized photons allows one to gain access to several observables in photonucleon reactions, which otherwise would not be measurable. The polarization axis defines a unique direction in space whereby the angular distributions of the final-state particles can be uniquely referenced. The polarization axis of the photon beam breaks the azimuthal symmetry of the reaction, thereby introducing an azimuthal ($\Phi$) dependence to the differential cross section. This additional information on the angular dependence opens the door to the measurement of a host of observables which are accessible only with a beam of linearly-polarized photons; consequently it provides important constraints on the nature of the photon-nucleon reaction. Such polarization observables are necessary for extracting the spin/parity of the broadly overlapping baryon resonances and measuring such parameters over a large energy range with full angular coverage is crucial for disentangling such contributions. 
 +
CoPI Cole is the contact person of the experiments which comprise the g8 run~\cite{Cole94,Ted98,FKlein99,Sanabria01,Pasyukg8,g8papers}. The scientific purpose of g8 is to improve the understanding of the underlying symmetry of the quark degrees of freedom in the nucleon, the nature of the parity exchange between the incident photon and the target nucleon, and the mechanism of associated strangeness production in electromagnetic reactions. With the high-quality beam of the tagged and collimated linearly-polarized photons and the nearly complete angular coverage of the Hall-B spectrometer, we seek to extract the differential cross sections and polarization observables for the photoproduction of vector mesons and kaons at photon energies ranging between 1.10 and 2.20~GeV.
  
−
CoPI Cole is the contact person of the experiments which comprise the g8
+
In preparation for the g8a run, we commissioned the Coherent Bremsstrahlung Facility, which was essentially a new beamline in Hall B for producing a tagged and collimated beam of linearly polarized photons, where the mean polarization in the energy range of 1.8 to 2.2~GeV was 71\%. We enjoyed a reasonably successful two-month run for g8a, which so far, has culminated in two Ph.D. theses~\cite{CGordon, JMelone}, two master's theses~\cite{APuga, JSalamanca}, and one of the two NSF graduate research fellowships~\cite{RMammei} awarded in nuclear physics in 2003.
−
run \cite{Cole94,Ted98,FKlein99,Sanabria01,Pasyukg8,g8papers}.
+
We seek to build upon our earlier work and investigate the nature of resonant baryon states by probing protons with polarized photons. The set of experiments forming the first phase of the g8 run took place in the summer of 2001 (6/04/01 - 8/13/01) in Hall B of Jefferson Lab. These experiments made use of a beam of linearly-polarized photons produced through coherent bremsstrahlung and represents the first time such a probe was employed at Jefferson Lab. The second time this probe was used took place in the summer of 2005 (6/20/05 - 9/01/05) for the second
−
The scientific purpose of g8 is to improve the understanding of the
+
phase of g8 (g8b), followed by g13b (3/08/07 - 6/29/07) and
−
underlying symmetry of the quark degrees of freedom in the nucleon, the
+
g9a (10/17/07 - 2/11/08). The g8 set of experiments, therefore, was a vital first step for establishing the Coherent Bremsstrahlung Facility and this experience paved the way for the successful runs with linearly polarized photons in Hall B of JLab: g13b ($\vec{\gamma}d$), and g9a ($\vec{\gamma}\vec{p}$). The lessons learned in calibration and cooking for g8b have accelerated the analyses for the g13a/b and g9a. And in the three years since the end of the g8b run, we have or are near completion of three Ph.D. theses: a) Craig Paterson~\cite{Paterson-g8b}, University of Glasgow, $\vec{\gamma}p \rightarrow K\Lambda, K\Sigma^{\circ}$, Aug.~2008), b) Patrick Collins~\cite{Collins-g8b}, Arizona State University, $ \vec{\gamma}p \rightarrow p\eta, p\eta^{\prime}$, Nov.~2008, and c) Juli\'{a}n Salamanca~\cite{Salamanca-g8b,LASNPA-7}, Idaho State University, $\vec{\gamma}p \rightarrow p\phi$, May~2009. \\
−
nature of the parity exchange between the incident photon and the target
 
−
nucleon, and the mechanism of associated strangeness production in
 
−
electromagnetic reactions. With the high-quality beam of the tagged and
 
−
collimated linearly-polarized photons and the nearly complete angular
 
−
coverage of the Hall-B spectrometer, we seek to extract the differential
 
−
cross sections and polarization observables for the photoproduction of
 
−
vector mesons and kaons at photon energies ranging between 1.10 and 2.20~GeV.
 
  
 +
\noindent \underline{\bf Photoproduction of the $\phi(1020)$} \\
 +
Vector meson photoproduction at high energies, as is well known, proceeds primarily through pomeron exchange rather than by $\pi$ or $\eta$ meson exchange, which are respectively termed natural and unnatural parity exchange. In the baryon resonance energy regime
 +
($E_{\vec{\gamma}}\sim 2.0$ GeV) and at low four-momentum transfer squared, $t$,
 +
the peak structure of the coherent $\phi$-meson photoproduction cross section
 +
is not well explained at threshold by a pure pomeron-exchange-based model~\cite{mibe}. The extraction of the Spin Density Matrix Elements (SDMEs) from $\phi$-meson decay angular distributions will shed light on the proportion of natural and unnatural parity exchange involved in the reaction mechanism~\cite{shilling} at low $t$, which is further to be compared to the predicted values of the Vector Dominance Model (VDM)~\cite{sakurai}.
 +
We have several thousand $\phi$s mesons at both low and high $t$
 +
in the baryon resonance regime of $2.02 < \sqrt{s} < 2.11$ GeV.  With the exception of this
 +
g8 dataset, there are no photoproduced phi mesons with linearly polarized photons measured in the central region in the world data set. Extracting the SDMEs for the phi channel at high $|t|$ will therefore hold discovery potential for non-VDM mechanisms at higher four-momentum transfers squared. 
 +
After making the necessary momentum, timing, particle ID, and Dalitz mass cuts we separate the data into unpolarized (AMO), perpendicular (PERP) polarization, and parallel (PARA) polarization. We fit a Breit-Wigner to the phi meson peak constrained with a decay width $\Gamma$ of 4.26~GeV with a second-order polynomial for fitting the background and a gaussian for representing the detector uncertainties. Below we display the phi peak obtained from extracting the $K^-$ from missing mass and then forming the invariant mass of the $K^+K^-$ separated in PERP and PARA orientations for the cms energy of $2.11 < \sqrt{s} < 2.20$~GeV.
  
 +
[[Image:phi_mass_para_perp.eps]]
  
−
In preparation for the g8a run, we commissioned the Coherent Bremsstrahlung
+
\begin{figure}[h!]
−
Facility, which was essentially a new beamline in Hall B
+
\begin{center}
−
for producing a tagged and collimated
+
\includegraphics[height=.18\textheight]{Graphs/Cole_phi_mass_para_perp.eps} \caption{\small $K^+K^-$ invariant mass in the cms energy range of $2.11 < \sqrt{s} < 2.20$~GeV fit with a Breit-Wigner + Gaussian + 2nd order polynomial. The decay width is fixed at 4.26~GeV. (RHS) parallel (LHS) perpendicular polarizations.} \label{fig:phi_mass} \end{center} \end{figure}
−
beam of linearly polarized photons, where the mean polarization in the
+
Below we plot the combination of parallel (PARA) and perpendicular (PERP) photoproduced phi mesons for all $t$ to obtain the photon beam asymmetry parameter: \\
−
energy range of 1.8 to 2.2~GeV was 71\%.  We enjoyed a reasonably
+
%\begin{equation}
−
successful two-month run for g8a, which so far, has culminated in two
+
$$\Sigma = (W^{PARA} - W^{PERP})/(W^{PERP} + W^{PARA}).$$
−
PhD theses~\cite{CGordon, JMelone}, two master's
+
%\end{equation}
−
theses~\cite{APuga, JSalamanca}, and one of the two NSF graduate research
+
These values are consistent with what we would expect from the Vector Dominance Model. We are presently working on separating the data into low- and high-$|t|$ regimes, but are not prepared to show it until we have authorization from the CLAS collaboration.
−
fellowships~\cite{RMammei} awarded in nuclear physics in 2003.
 
  
−
We seek to build upon our earlier work and investigate the nature of
+
[[Image:asym_all.eps]]
−
resonant baryon states by probing protons with polarized photons.
 
−
The set of experiments forming the first phase of the g8 run took place
 
−
in the summer of 2001 (6/04/01 - 8/13/01) in Hall B of Jefferson Lab.
 
−
These experiments made use of a beam of linearly-polarized photons produced
 
−
through coherent bremsstrahlung and represents the first time such a probe
 
−
was employed at Jefferson Lab.  The second time this probe was used
 
−
took place in the summer of 2005 (6/20/05 - 9/01/05) for the second
 
−
phase of g8 (g8b), followed by g13b (3/08/07 - 6/29/07) and
 
−
g9a (10/17/07 - 2/11/08).  The g8 set of experiments, therefore, was a vital
 
−
first step
 
−
for establishing the Coherent Bremsstrahlung Facility and this
 
−
experience paved the way for the successful runs with linearly
 
−
polarized photons in Hall B of JLab: g13b ($\vec{\gamma}d$), and
 
−
g9a ($\vec{\gamma}\vec{p}$).  The lessons learned in calibration and
 
−
cooking for g8b  have accelerated the analyses for the g13a/b and g9a.
 
−
And in the three years since the end of the g8b run, we have generated
 
−
or are near completion of three PhD theses:  a)
 
−
Craig Paterson~\cite{Paterson-g8b}, University of Glasgow,
 
−
$\vec{\gamma}p \rightarrow K\Lambda, K\Sigma^{\circ}$, Aug.~2008),
 
−
b) Patrick Collins~\cite{Collins-g8b}, Arizona State University,
 
−
$ \vec{\gamma}p \rightarrow p\eta, p\eta^{\prime}$, Nov.~2008, and
 
−
c) Juli\'{a}n Salamanca~\cite{Salamanca-g8b,LASNPA-7},
 
−
Idaho State University, $\vec{\gamma}p \rightarrow p\phi$, May~2009. \\
 
−
 
 
−
\medskip
 
−
 
 
−
\noindent
 
−
\underline{\bf Photoproduction of the $\phi(1020)$} \\
 
  
−
Vector meson photoproduction at high energies, as is well known, is
+
\begin{figure}[h!]
−
proceeds primarily through pomeron exchange rather by $\pi$ or $\eta$ meson
+
\begin{center}
−
exchange, which are respectively termed natural and unnatural parity exchange.
+
\includegraphics[height=.18\textheight]{Graphs/Cole_asym_all.eps}
−
In the baryon resonance energy regime ($\sim E_{\vec{\gamma}}=2.0$ GeV) and
+
\caption{\small Beam asymmetry for the phi meson channel over the full range of $t$ for (a) $1.9 < E_{\gamma} < 2.1$~GeV and (b) $1.7 < E_{\gamma} <1.9$~GeV. The photon beam polarization is 75\%.}
−
at low four-momentum squared transfer, $t$,
+
\label{fig:asym} \end{center} \end{figure}
−
peak structure of coherent $\phi$-meson photoproduction cross section
 
−
around is not well explained by a pure pomeron-exchange-based model\cite{mibe}.
 
−
The extraction of the Spin Density Matrix Elements (SDMEs) from
 
−
$\phi$-meson decay angular distributions will shed light on the proportion of
 
−
natural and unnatural parity exchange involved in the reaction
 
−
mechanism\cite{shilling} at low $t$, which  is further to be compared  to the predicted
 
−
values of the Vector Dominance Model (VDM)~\cite{sakurai}.    This is to say
 
−
besides the approximately 2700 (3700) $\phi$s in the energy range of $2.02 < \sqrt{s} < 2.11$ GeV
 
−
( $2.11 < \sqrt{s} < 2.20$~GeV) in the low-$t$ regime i.e.~$|t - t_{\rm min}|  < 0.6$~GeV$^2$, we
 
−
have approximately 700 (1700) $\phi$ mesons in these respective energy ranges for the central,
 
−
non-VDM regime, i.e.~$|t - t_{\rm min}| > 0.6$~GeV$^2$.  And outside this g8b dataset, there are
 
−
no photoproduced phi mesons with linearly polarized photons measured in the central region in the
 
−
world data set.  Extracting the SDMEs
 
−
for the phi channel at high $|t|$ will therefore hold
 
−
discovery potential for non-VDM mechanisms at higher four-momentum squared transfers.
 
  
−
After making the necessary momentum, timing, particle ID, and Dalitz mass cuts we separate the
 
−
data into unpolarized (AMO), perpendicular (PERP) polarization and parallel (PARA) polarization.
 
−
We fit a Breit-Wigner to the phi meson peak (constrained with a decay width $\Gamma$ of 4.26~GeV
 
−
with a second-order polynomial for fitting the background and a gaussian for representing the detector
 
−
uncertainties.  Below we display the phi peak obtained from extracting the $K^-$ from missing mass
 
−
and then forming the invariant mass of the $K^+K^-$ separated in PERP and PARA orientations for
 
−
the cms energy of $2.11 < \sqrt{s} < 2.20$~GeV.
 
  
−
[[Image:phi_mass_para_perp.eps]]
 
  
−
\begin{figure}[h!]
 
−
\begin{center}
 
−
\includegraphics[height=.18\textheight]{phi_mass_para_perp.eps}
 
−
\caption{\small $K^+K^-$ invariant mass in the cms energy range of $2.11 < \sqrt{s} < 2.20$~GeV fit with a
 
−
Breit-Wigner + Gaussian + 2nd order polynomial.  The decay width is fixed 4.26~GeV.
 
−
(RHS) parallel (LHS) perpendicular polarizations.}
 
−
\label{fig:phi_mass}
 
−
\end{center}
 
−
\end{figure}
 
  
−
Below we plot the combination of  parallel (PARA) and perpendicular (PERP) photoproduced phi mesons for all
 
−
$t$ to obtain the photon beam asymmetry parameter:
 
−
$\Sigma = (W^{PARA} - W^{PERP})/(W^{PERP} + W^{PARA})$  These values are consistent with
 
−
what we would expect from the Vector Dominance Model.  We are presently working on separating the data into
 
−
low- and high-$|t|$ regimes, but are not prepared to show it until we have authorization from the
 
−
CLAS collaboration.
 
  
−
[[Image:asym_all.eps]]
 
  
−
\begin{figure}[h!]
 
−
\begin{center}
 
−
\includegraphics[height=.18\textheight]{asym_all.eps}
 
−
\caption{\small Beam asymmetry for the phi meson channel over the
 
−
full range of $t$ for (a) $1.9 < E_{\gamma} < 2.1$~GeV and
 
−
(b) $1.7 < E_{\gamma} <1.9$~GeV.  The photon beam polarization is 75\%.}
 
−
\label{fig:asym}
 
−
\end{center}
 
−
\end{figure}
 
  
 
=== Primakoff===
 
=== Primakoff===
  
−
\section{The {\em PrimEx} Experiment}
+
CoPI Dale is a spokesperson for the {\em PrimEx} Collaboration. At present, the scientific goal of the Collaboration is to perform a high precision measurement of the neutral pion lifetime as a test of the chiral anomaly in QCD, along with different approaches to corrections to the anomaly.
−
 
 
−
One of the Co-PI's for this proposal (D. Dale) is a spokesperson for the {\em PrimEx} Collaboration.
 
−
At present, the scientific goal of the Collaboration is to perform a high precision measurement
 
−
of the neutral pion lifetime as a test of the chiral anomaly in QCD, along with different approaches to  
 
−
corrections to the anomaly.
 
−
 
 
  
−
 
+
The two-photon decay mode of the $\pi^{0}$ reveals one of the most profound symmetry issues in quantum chromodynamics, namely, the explicit breaking of a classical symmetry by the quantum fluctuations of the quark fields coupling to a gauge field~\cite{book}. This phenomenon, called anomalous symmetry breaking, is of pure quantum mechanical origin. The axial anomaly of interest to us involves the corresponding coupling of the quarks to photons~\cite{anomaly}. In the limit of exact isospin symmetry, the $\pi^{o}$ couples only to the isotriplet axial-vector current
−
The two-photon decay mode of the $\pi^{0}$ reveals one of the most
+
$\bar{q}I_3\gamma_\mu \gamma_5 q$, where $q=(u,\; d)$, and
−
profound
+
$I_3$ is the third isospin generator. In the
−
symmetry issues in quantum chromodynamics,  
+
limit of two quark flavors, the electromagnetic current is given by $\bar{q}(1/6+ I_3/2)\gamma_\mu q$. When coupling to the photon,
−
namely, the explicit breaking of a classical
+
the isosinglet and isotriplet components of the electromagnetic
−
symmetry
 
−
by the quantum fluctuations of the quark fields coupling to
 
−
a gauge field\cite{book}. This phenomenon, called anomalous
 
−
symmetry breaking,
 
−
is of pure quantum mechanical origin.  
 
−
The axial anomaly of interest to us involves the
 
−
corresponding coupling of the
 
−
quarks to photons\cite{anomaly}.
 
−
In the limit of exact isospin symmetry, the $\pi^{o}$ couples only to the isotriplet axial-vector current
 
−
$\bar{q}I_3\gamma_\mu \gamma_5 q$, where $q=(u,\; d)$, and
 
−
$I_3$ is the third isospin generator. In the
 
−
limit of two quark flavors, the electromagnetic current
 
−
is given by $\bar{q}(1/6+ I_3/2)\gamma_\mu q$. When
 
−
coupling to the photon,
 
−
the isosinglet and isotriplet components of the electromagnetic
 
 
current
 
current
−
lead to an anomaly that explicitly breaks the symmetry associated
+
lead to an anomaly that explicitly breaks the symmetry associated
 
with the axial-vector current
 
with the axial-vector current
−
  $\bar{q}\;I_3\;\gamma_\mu \gamma_5\;q$, and this in turn
+
$\bar{q}\;I_3\;\gamma_\mu \gamma_5\;q$, and this in turn
−
  directly affects the coupling of the $\pi^{o}$ to two photons. The conservation of the  axial U(1) current,
+
directly affects the coupling of the $\pi^{o}$ to two photons. The conservation of the  axial U(1) current,
−
to which the $\eta'$ meson couples,  as well as the
+
to which the $\eta'$ meson couples,  as well as the
−
$\bar{q} \frac{1}{2}\lambda_{8}\gamma_\mu \gamma_5 q$, to which the $\eta$ meson couples, are similarly affected  
+
$\bar{q} \frac{1}{2}\lambda_{8}\gamma_\mu \gamma_5 q$, to which the $\eta$ meson couples, are similarly affected by the electromagnetic field.
−
by the electromagnetic field.
 
−
 
 
−
 
 
−
  For vanishing quark masses, the anomaly leads to the
 
−
the predicted width of the $\pi^{o} \rightarrow \gamma \gamma$
 
−
decay:
 
−
 
 
−
\begin{equation}
 
−
\Gamma=M_{\pi}^{3}\frac{ \mid A_{\gamma \gamma}
 
−
\mid^{2}}{64\pi}= 7.725 \pm 0.044 eV,
 
−
\end{equation}
 
  
 +
For vanishing quark masses, the anomaly leads to the
 +
predicted width of the $\pi^{o} \rightarrow \gamma \gamma$ decay:
 +
\begin{equation} \Gamma=M_{\pi}^{3}\frac{ \mid A_{\gamma \gamma} \mid^{2}}{64\pi}= 7.725 \pm 0.044 ~\rm{eV}, \end{equation}
 
where the reduced amplitude is
 
where the reduced amplitude is
 +
\begin{equation} A_{\gamma \gamma} =\frac{\alpha_{em}}{\pi F_{\pi}} = 2.513 \cdot 10^{-2} ~\rm{GeV}^{-1} \end{equation}
  
−
\begin{equation}
+
In this expression, there are no free parameters. Since the mass of the $\pi^0$ is the smallest in the hadron spectrum, higher order corrections to this prediction are small and can be calculated with sub-percent accuracy.
−
A_{\gamma \gamma} =\frac{\alpha_{em}}{\pi F_{\pi}} = 2.513 \cdot
+
The current experimental
−
10^{-2} GeV^{-1}
+
value is $7.84 \pm 0.56$ eV~\cite{PDB} and is in good agreement with the predicted value with the chiral limit amplitude. This number is an average of several experiments~\cite{PDB}. Even at the 7\% level quoted by the Particle Data Book~\cite{PDB}, the accuracy is not sufficient for a test of the new calculations which take the finite quark masses into account. The level of precision of $\simeq 1.4\%$, which is the goal of {\em PrimEx}, will satisfy these requirements.
−
\end{equation}
+
Stimulated by the
−
 
+
{\em PrimEx} project, several new theoretical calculations have been published in recent years, and are shown in Figure~\ref{fig:theory}. The first two independent
 +
  calculations of the chiral corrections were performed in the 
 +
combined framework of chiral perturbation theory (ChPT) and the $1/N_c$ expansion up to ${\cal{O}}(p^6)$ and ${\cal{O}}(p^4\times 1/N_c)$ in the decay amplitude~\cite{Goity}~\cite{Mou02}. The $\eta'$ is explicitly included in the analysis as it plays as important a role as the $\eta$ in the mixing effects. It was found that the decay width is enhanced by about 4\% with respect to the value stated in equation (1). This enhancement is almost entirely due to the mixing effects. The result of this next-to-leading order analysis is $\Gamma_{\pi^0\to\gamma\gamma}=8.10~ {\rm eV}$ with an estimated uncertainty of less than 1\%. Another theoretical calculation based on QCD sum rules~\cite{Ioffe07}, also inspired by the {\em PrimEx} experiment, has recently been published with a theoretical uncertainty less than 1.5\%. Here, the only input parameter to the calculation is the $\eta$ width.
  
−
In this expression, there are no free parameters. Since the mass of
 
−
the $\pi^0$ is the smallest
 
−
in the hadron spectrum, higher order corrections to this prediction are small and
 
−
can be calculated with a
 
−
sub-percent accuracy.
 
  
−
The current experimental
 
−
value is $7.84 \pm 0.56$ eV\cite{PDB} and is in good
 
−
agreement with the predicted value with the chiral limit amplitude. This number
 
−
is an average of several experiments\cite{PDB}. 
 
−
Even at the 7\% level quoted by the Particle Data Book\cite{PDB}, the accuracy is
 
−
not sufficient for a test of the new calculations which take the finite quark masses into
 
−
account. The level of precision of $\simeq 1.4\%$, which is the goal of 
 
−
{\em PrimEx}, will satisfy these requirements.
 
−
 
−
Stimulated by the
 
−
{\em PrimEx} project,  several new theoretical calculations have been published in recent years, and are shown in
 
−
figure \ref{fig:theory}.
 
−
The first two independent
 
−
  calculations of the chiral corrections were performed in the 
 
−
combined framework of chiral perturbation theory (ChPT) and the $1/N_c$
 
−
expansion up to ${\cal{O}}(p^6)$ and
 
−
${\cal{O}}(p^4\times 1/N_c)$ in the decay amplitude\cite{Goity}\cite{Mou02}. The
 
−
$\eta'$ is explicitly included in the analysis as it plays as important a
 
−
role as the $\eta$ in the mixing effects. It was found that the
 
−
decay width is enhanced by about 4\% with respect to the value stated in
 
−
equation (1).
 
−
This enhancement is almost entirely due to the mixing effects.
 
−
The result of this next-to-leading order analysis  is 
 
−
$\Gamma_{\pi^0\to\gamma\gamma}=8.10~ {\rm eV}$ with an
 
−
estimated  uncertainty of less than 1\%. Another theoretical
 
−
calculation based on QCD  sum rules\cite{Ioffe07}, also inspired by the {\em PrimEx}
 
−
experiment, has recently been published with a theoretical uncertainty less than 1.5\%.
 
−
Here, the only input parameter to the calculation is the $\eta$ width.
 
  
 
[[Image:pio_width_new_theory_prel_result.eps]]
 
[[Image:pio_width_new_theory_prel_result.eps]]
  
 
\begin{figure}
 
\begin{figure}
−
\centering
+
\begin{center}
−
\psfig{figure=pio_width_new_theory_prel_result.eps,height=6.0in,width=6.0in}
+
%\begin{minipage}[t]{0.58\linewidth}
−
\caption{$\pi^{o} \rightarrow \gamma \gamma$ decay width in eV. The  
+
\begin{minipage}[t]{0.38\linewidth}
 +
\scalebox{0.5} [0.55]{\includegraphics{Graphs/Pio_width_new_theory_prel_result.eps}}
 +
%\epsfig{file=Graphs/Pio_width_new_theory_prel_result.eps,width=\linewidth}
 +
\end{minipage}\hfill
 +
%\begin{minipage}[t]{0.38\linewidth}
 +
\begin{minipage}[t]{0.48\linewidth}
 +
\vspace*{-10cm}\caption{$\pi^{o} \rightarrow \gamma \gamma$ decay width in  
 +
eV. The  
 
dashed horizontal line is the leading order prediction  
 
dashed horizontal line is the leading order prediction  
−
of the axial anomaly (equation 3)\cite{book,  
+
of the axial anomaly~\cite{book,  
−
anomaly}.The left hand side shaded band is the recent QCD sum rule prediction and the
+
anomaly}.The left hand side shaded band is the recent QCD sum rule  
−
right hand side shaded band is the  next-to-leading order chiral theory predictions.
+
prediction and the
−
The experimental results with errors are for : (1)~the direct method\cite{At85};
+
right hand side shaded band is the  next-to-leading order chiral theory  
−
(2, 3, 4)~the Primakoff method \cite{Br74,Bel70,Kr70}; (5)~the preliminary result from the first
+
predictions.
 +
The experimental results with errors are for : (1)~the direct  
 +
method~\cite{At85};
 +
(2, 3, 4)~the Primakoff method~\cite{Br74,Bel70,Kr70}; (5)~the preliminary  
 +
result from the first
 
{\em PrimEx} data set;
 
{\em PrimEx} data set;
 
(6)~the expected  
 
(6)~the expected  
−
error for the final goal of the {\em PrimEx} experiment, arbitrarily plotted to agree with  
+
error for the final goal of the {\em PrimEx} experiment, arbitrarily  
−
the leading order prediction.}
+
plotted to agree with  
−
\label{fig:theory}
+
the leading order prediction. prediction.\label{fig:theory}}
 +
\end{minipage}
 +
\label{fig:Primextheory}
 +
\end{center}
 
\end{figure}
 
\end{figure}
  
Line 565: Line 392:
  
  
−
 
+
We are using quasi-monochromatic photons of energy 4.6-5.7~GeV from the Hall~B photon tagging facility to measure the absolute cross section of small angle $\pi^{o}$ photoproduction from the Coulomb field of complex nuclei. The invariant mass and angle of the pion are reconstructed by detecting the $\pi^{o}$ decay photons from the $\pi^{o} \rightarrow \gamma \gamma$ reaction.
−
 
 
−
 
 
−
 
 
−
 
 
−
 
 
−
We are using quasi-monochromatic photons of energy 4.6-5.7~GeV  
 
−
from the Hall~B photon tagging facility to measure the absolute cross section  
 
−
of small angle $\pi^{o}$ photoproduction from the Coulomb field of complex  
 
−
nuclei. The invariant mass and angle of the pion are reconstructed by  
 
−
detecting the $\pi^{o}$ decay photons from the $\pi^{o} \rightarrow \gamma  
 
−
\gamma$ reaction.
 
−
 
 
 
For unpolarized photons, the Primakoff cross section is given by:
 
For unpolarized photons, the Primakoff cross section is given by:
−
 
+
\begin{equation} \frac{d\sigma_P}{d\Omega}=\Gamma_{\gamma \gamma}\frac{8{\alpha}Z^2}{m^3}\frac{\beta^3{E^4}}{Q^4}|F_{e.m.}(Q)|^ 2 \sin^{2}\theta_{\pi} \end{equation}
−
\begin{equation}
+
\noindent where $\Gamma_{\gamma \gamma}$ is the pion decay width, $Z$ is the atomic number, $m$, $\beta$, $\theta_{\pi}$ are the mass, velocity and production angle of the pion, $E$ is the energy of incoming photon, $Q$ is the momentum transfer to the nucleus, and $F_{e.m.}(Q)$ is the nuclear electromagnetic form factor, corrected for final state interactions of the outgoing pion.
−
\frac{d\sigma_P}{d\Omega}=\Gamma_{\gamma  
+
As the Primakoff effect is not the only mechanism for pion photoproduction at high energies, some care must be taken to isolate it from competing processes. In particular, the full cross section is given by:
−
\gamma}\frac{8{\alpha}Z^2}{m^3}\frac{\beta^3{E^4}}{Q^4}|F_{e.m.}(Q)|^
+
\begin{equation} \frac{d\sigma}{d\Omega_{\pi}} = \frac{d \sigma_P}{d\Omega} + \frac{d\sigma_C}{d \Omega} + \frac{d \sigma_I}{d\Omega}+ 2 \cdot \sqrt{\frac{d\sigma_{P}}{d\Omega} \cdot \frac{d\sigma_{C}}{d\Omega}} cos(\phi_1 + \phi_2) \end{equation}
−
2 sin^{2}\theta_{\pi}
+
\noindent where the Primakoff cross section, $\frac{d \sigma_P}{d\Omega}$, is given by equation (4). The nuclear coherent cross section is given by: \begin{equation} \frac{d\sigma_C}{d \Omega} = C \cdot A^2 |F_N(Q)|^2 \sin^2\theta_{\pi} \end{equation} and the incoherent cross section is: \begin{equation}
−
\end{equation}
+
\frac{d \sigma_I}{d\Omega}=\xi A (1-G(Q)) \frac{d  
−
 
+
\sigma_H}{d\Omega} \end{equation} where $A$ is the nucleon number, $C \sin^2\theta_{\pi}$ is the square of the isospin and spin independent part of the neutral meson photoproduction amplitude on a single nucleon, $|F_N(Q)|$ is the form factor for the nuclear matter distribution in the nucleus, (corrected for final state interactions of the outgoing pion), $\xi$ is the absorption factor of the incoherently produced pions, $1-G(Q)$ is a factor which reduces the cross section at small momentum transfer due to the Pauli exclusion principle, and $\frac{d \sigma_H}{d\Omega}$ is the $\pi^o$ photoproduction cross section on a single nucleon. The relative phase between the Primakoff and nuclear coherent amplitudes without final state interactions is given by $\phi_1$, and the phase shift of the outgoing pion due to final state interactions is given by $\phi_2$.
−
\noindent
+
The angular dependence of the Primakoff signal is different from the background processes, allowing $\Gamma(\pi^0\rightarrow \gamma\gamma)$ to be extracted from a fit to the angular distribution of photo-produced $\pi^0$. Measurements of the nuclear effects at larger angles are necessary to determine the unknown parameters in the production mechanism and thus make an empirical determination of the nuclear contribution in the Primakoff peak region. Consequently, this experiment uses a $\pi^{o}$ detector with good angular resolution to eliminate nuclear coherent production, and good energy resolution in the decay photon detection will enable an invariant mass cut to suppress multi-photon backgrounds.
−
where $\Gamma_{\gamma \gamma}$ is the pion decay width, $Z$ is the atomic
+
%Image:Primex pb cross color.ps
−
number, $m$, $\beta$, $\theta_{\pi}$ are the mass, velocity and production  
+
%\begin{figure} %\centerline{\epsfxsize=200pt \epsfbox[200 150 430 500]{pb_cross_color.ps}} %\vspace{1cm} %\caption{Angular behavior of the electromagnetic and nuclear %$\pi^o$ photoproduction cross sections for %$^{208}$Pb in the 6.0~GeV energy range. } %\label{fig3} %\end{figure}
−
angle of the pion, $E$ is the energy of incoming photon, $Q$ is the momentum  
 
−
transfer to the nucleus, and $F_{e.m.}(Q)$ is the nuclear electromagnetic form  
 
−
factor, corrected for final state interactions of the outgoing pion.
 
−
 
 
−
As the Primakoff effect is not the only mechanism for pion photoproduction at
 
−
high energies, some care must be taken to isolate it from competing processes.
 
−
In particular, the full cross section is given by:
 
−
 
 
−
\begin{equation}
 
−
\frac{d\sigma}{d\Omega_{\pi}} = \frac{d \sigma_P}{d\Omega} +
 
−
\frac{d\sigma_C}{d \Omega} + \frac{d \sigma_I}{d\Omega}+
 
−
2 \cdot \sqrt{\frac{d\sigma_{P}}{d\Omega} \cdot
 
−
\frac{d\sigma_{C}}{d\Omega}} cos(\phi_1 + \phi_2)
 
−
\end{equation}
 
−
 
 
−
\noindent
 
−
where the Primakoff cross section, $\frac{d \sigma_P}{d\Omega}$, is given by  
 
−
equation (4). The nuclear coherent cross section is given by:
 
−
\begin{equation}
 
−
\frac{d\sigma_C}{d \Omega} = C \cdot A^2 |F_N(Q)|^2  
 
−
sin^2\theta_{\pi}
 
−
\end{equation}
 
−
and the incoherent cross section is:
 
−
\begin{equation}
 
−
\frac{d \sigma_I}{d\Omega}=\xi A (1-G(Q)) \frac{d  
 
−
\sigma_H}{d\Omega}
 
−
\end{equation}
 
−
where $A$ is the nucleon number, $C sin^2\theta_{\pi}$ is the square  
 
−
of the isospin and spin independent part
 
−
of the neutral meson photoproduction amplitude on a single nucleon,
 
−
$|F_N(Q)|$ is the form factor for the nuclear matter distribution in the  
 
−
nucleus, (corrected for final state interactions of the outgoing pion),  
 
−
$\xi$ is the absorption factor of the incoherently produced pions,  
 
−
$1-G(Q)$ is a factor which reduces the cross section at small momentum transfer  
 
−
due to the Pauli exclusion principle, and $\frac{d \sigma_H}{d\Omega}$
 
−
is the $\pi^o$ photoproduction cross section on a single nucleon. The  
 
−
relative phase between the Primakoff and nuclear coherent amplitudes without  
 
−
final state interactions is given by $\phi_1$, and the
 
−
phase shift of the outgoing pion due to final state interactions  
 
−
is given by $\phi_2$.
 
−
 
 
−
The angular dependence of the Primakoff signal is different from the background processes,  
 
−
allowing $\Gamma(\pi^0\rightarrow \gamma\gamma)$ to be extracted from a fit to the angular  
 
−
distribution
 
−
of photo-produced $\pi^0$.
 
−
Measurements of the nuclear effects at larger angles are necessary to
 
−
determine the unknown parameters in the production mechanism  
 
−
and thus make an empirical determination of the nuclear contribution in the
 
−
Primakoff peak region. Consequently, this experiment uses a $\pi^{o}$  
 
−
detector with good angular resolution to eliminate nuclear coherent production,  
 
−
and good energy resolution in the decay photon detection will enable an  
 
−
invariant mass cut to suppress multi-photon backgrounds.
 
−
 
 
−
[[Image:Primex_pb_cross_color.ps]]
 
−
 
 
−
%\begin{figure}
 
−
%\centerline{\epsfxsize=200pt \epsfbox[200 150 430 500]{pb_cross_color.ps}}
 
−
%\vspace{1cm}
 
−
%\caption{Angular behavior of the electromagnetic and nuclear  
 
−
%$\pi^o$ photoproduction cross sections for  
 
−
%$^{208}$Pb in the 6.0~GeV energy range. }
 
−
%\label{fig3}
 
−
%\end{figure}
 
−
 
 
  
 
We submitted our first proposal (E-99-014) to PAC15 in December of 1998. It was approved by PAC15 and
 
We submitted our first proposal (E-99-014) to PAC15 in December of 1998. It was approved by PAC15 and
−
reconfirmed in  jeopardy review later by PAC22  with an ``A'' rating. An NSF MRI proposal for \$970k
+
reconfirmed in  jeopardy review later by PAC22  with an ``A'' rating. An NSF MRI proposal for \$970k
−
was awarded (PIs: D. S. Dale, A. Gasparian, R. Miskimen, S. Dangoulian) for the construction
+
was awarded (PIs: D.S.~ Dale, A.~Gasparian, R.~Miskimen, S.~Dangoulian) for the construction of a multichannel neutral pion calorimeter. This was successfully designed, constructed, and commissioned over the period 2000-2004. The first experiment on two targets ($^{12}$C and $^{208}$Pb) was performed in 2004. A second run (E-08-023, spokespersons: D.~Dale, A.~Gasparian, M.~Ito, R.~Miskimen) was approved by PAC33 with an $A-$ rating for 20 days of running to reach the proposed goal of $\sim 1.4\%$ accuracy. While the CoPI of this funding proposal has been involved in all aspects of this program, he has taken primary responsibility for the flux normalization. This has involved the design, construction, and commissioning of the {\em PrimEx} pair spectrometer. In addition, along with his students, he has been responsible for the analysis of the resulting data. This has also included a high precision measurement of the absolute cross section of a well known QED process, pair production, to verify that the flux determination was correct.  
−
of a multichannel neutral pion calorimeter. This was successfully designed, constructed, and commissioned
+
%To date, the CoPI has supervised to completion one Ph.D. student (A. Teymurazyan) and one M.S. student on this work. One more Ph.D. student (O. Kosinov) is currently working toward his degree.
−
over the period 2000-2004. The first experiment  
 
−
on two targets ($^{12}$C and $^{208}$Pb) was performed in 2004. A second run (E-08-023,
 
−
spokespersons: D. Dale, A. Gasparian, M. Ito, R. Miskimen)  
 
−
was approved by PAC33 with an $A-$ rating for 20 days of running to reach the
 
−
proposed goal of $\sim 1.4\%$ accuracy.
 
−
While the Co-PI of this funding proposal has been involved in all aspects of this program, he has taken
 
−
primary responsibility for the flux normalization. This has involved the design, construction, and
 
−
commissioning of the {\em PrimEx} pair spectrometer. In addition, along with his students, he has been
 
−
responsible to the analysis of the resulting data. This has also included a high precision measurement
 
−
of the absolute cross section of a well known QED process, pair production, to verify that the
 
−
flux determination was correct. To date, the co-PI has supervised to completion one Ph.D. student
 
−
(A. Teymurazyan) and one M.S. student on this work. One more Ph.D. student (O. Kosinov) is currently
 
−
working toward his degree.
 
  
  
  
  
−
\bibitem{book} See {\sl e.g.} Dynamics of the Standard Model,
 
−
J.F. Donoghue,
 
−
E. Golowich, and B.R. Holstein, Cambridge University Press (1992).
 
  
−
\bibitem{anomaly} J.S. Bell and R. Jaciw, Nuovo Cimento 60A, 47
 
−
(1969). S.L. Adler, Phys. Rev. 177, 2426 (1969).
 
  
  
−
\bibitem{PDB} R.M. Barnett {\sl et al.}, Review of Particle Physics, Phys.
 
−
Rev. D54,1 (1996).
 
−
`
 
−
\bibitem{Goity} J. L. Goity, A. M. Bernstein, J. F. Donoghue,
 
−
and B. R. Holstein, manuscript in preparation;
 
−
J. L. Goity, talk at Baryons 2002.
 
  
−
\bibitem{Mou02}B. Ananthanarayan and B. Moussallam, preprint hep-ph/0205232.
 
  
  
−
\bibitem{Ioffe07}B.L. Ioffe and A.G. Oganesian, Phys. Lett. B647, (2007) 389.
 
  
  
  
−
\bibitem{At85} H.W. Atherton {\sl et al.}, Phys. Lett., vol. 158B, no. 1,
+
== Prior and Future use of NSF Funds==
−
(1985), 81.
 
−
 
 
−
 
 
−
\bibitem{Br74} A. Browman et al., Phys. Rev. Letts., vol. 33, no. 23, (1974),
 
−
1400
 
  
−
\bibitem{Bel70} G. Bellettini et al., Il Nuovo Cimento, vol. 66, no. 1,
 
−
(1970), 243.
 
−
 
−
\bibitem{Kr70} V.I. Kryshkin {\sl et al.}, Sov. Phys. JETP, vol. 30, no. 6,
 
−
(1970),1037.
 
−
 
−
== Prior and Future use of NSF Funds==
 
 
[[Image:BremFacility.jpg | 200 px]][[Image:PairSpectrometer_NSF08.jpg| 200 px]][[Image:Qweak_BottomDetector_HVboard_Cathode_and_Bolts_2.jpg|200px]]
 
[[Image:BremFacility.jpg | 200 px]][[Image:PairSpectrometer_NSF08.jpg| 200 px]][[Image:Qweak_BottomDetector_HVboard_Cathode_and_Bolts_2.jpg|200px]]
  
Line 717: Line 430:
  
 
=== Prior use of NSF funds===
 
=== Prior use of NSF funds===
−
The PI's in this proposal have a strong record of receiving external funding from the NSF and a history of effectively using those funds to make substantially contributions to the infrastructure of the nuclear physics program described in this proposal.  The bremsstrahlung facility in JLAB's Hall-B is one example of Dr. Cole's efforts to enhance the capabilities of Hall B's photon physics program.  Dr. Dale has used NSF funds to install a pair spectrometer facility in Hall B. The region 1 tracking system for Qweak was constructed by Dr. Forest using NSF funds.
+
\begin{figure}[htbp]
 +
%\vspace{-1in}
 +
\begin{center}
 +
{
 +
\scalebox{0.2} [0.4]{\includegraphics{Graphs/Cole_BremHist.eps}}
 +
\scalebox{0.25} [0.25]{\includegraphics{Graphs/DalePairSpect.eps}}
 +
\scalebox{0.15} [0.15]{\includegraphics[angle=90]{Graphs/QweakAssembledDetector.eps}}
 +
}
 +
\caption{The histograms show the improvement to Hall B's  
 +
linearly polarized photon beam using the collimator designed and calibrated by CoPI Cole.   
 +
The middle picture shows the pair spectrometer system installed in Hall B by CoPI Dale and his collaborators.
 +
The right most picture is of an assembled GEM detector for $Q_{weak}$'s Region 1 tracking system designed,
 +
machined and assembled by PI Forest and his students at ISU.
 +
}
 +
\label{fig:PriorNSFProducts}
 +
\end{center}
 +
\end{figure}
  
  
−
While at Louisiana Tech University, Dr. Forest received three prior NSF awards as a member of the Louisiana Tech Particle Physics Group. The first proposal entitled ``Parity Violating Electron Scattering at Jefferson Lab, was awarded in 2002 for three years in the amount of \$670,230 (NSF Award \#0244998) to Louisiana Tech University. The award supported the groups efforts building triggering electronics for the G0 backward angle measurements and for the initial development of the $Q_{weak}$ experiment. The second proposal, ``Precision Electroweak Measurements at Jefferson Lab, was awarded \$204,594 in 2006 (NSF Award \#0555390) with similar support for the next two years to continuing the Lousiana Group's efforts. Dr. Forest's MRI Proposal (\#PHYS-0321197) entitled {\small ``Collaborative Research:Development of a Particle Tracking System for the Qweak Experiment} was awarded \$131,770 on July 26, 2003 to develop the Region 1 tracking system for the Q$_{weak}$ experiment. After moving to ISU, Dr. Forest recieved a grant to continue his research efforts on Qweak as well as hist work Semi-inclusive Deep Inelastic Scattering. The status of the work supported by the above awards which the Dr. Forest was responsible for is given in section~\ref{section:QweakDetector} and shown in Figure~\ref{fig:QweakProducts}
 
  
−
==== Qweak Detector Construction====
+
The PIs in this proposal have a strong record of receiving external funding from the  
−
The design, construction, and testing of the Region 1 tracking system for the Qweak experiment at Jefferson Lab has been the main research activity supported by Dr. Forest's previous NSF grant. The Qweak Region 1 tracking system is one of three tracking systems designed to measure the Q2 profile of elastically scattered electrons as well as background contributions to the parity violating signal~\cite{QweakProposal}. The Region 1 tracking system is located behind the first collimator at a distance of about 550 cm from the main torus magnet ( 200 cm from the target).  
+
NSF and a history of  
−
The high radiation flux and the small detector footprint are two of the biggest challenges facing the Region 1 tracking system. As a result, an ionization chamber equipped with Gas Electron Multipliers (GEM) was chosen in order to accommodate the high radiation flux near the target. The GEM preamplifiers allow smaller ionization cell sizes thereby resulting in ionization chamber rise times of 50 nanoseconds or less.  
+
effectively using those funds to make substantially
−
The figure below shows the custom designed GEM detector for the Qweak Region 1 tracking system.  Engineers from the Idaho Accelerator Center (IAC) designed the GEM preamplifiers and is a clear example of how the infrastructure at the IAC can be leveraged in support of our physics mission. The remaining detector design, machinging, and assembly was completed using by both graduate and undergraduate students as described in this years NSF project report.
+
contributions to the infrastructure of the nuclear
 +
physics program described in this proposal, as summarized in Figure~\ref{fig:PriorNSFProducts}.  
 +
The bremsstrahlung facility in JLab's Hall-B is one example
 +
of CoPI Cole's efforts to enhance the capabilities of Hall B's photon physics program. CoPI Dale has used NSF
 +
funds to install a pair spectrometer facility in Hall B. The Region 1 tracking system for $Q_{weak}$ was  
 +
constructed by PI Forest using NSF funds.
  
−
====pair spectrometer====
 
−
In 2000, an NSF MRI proposal (grant \# PHY-0079840) for \$970k
 
−
was awarded (PIs: D. S. Dale, A. Gasparian, R. Miskimen, S. Dangoulian)
 
−
for the construction
 
−
of a multichannel neutral pion calorimeter, a pair spectrometer for flux
 
−
monitoring, as well as a number of other pieces of experimental
 
−
instrumentation for the {\em PrimEx} experiment. Dr. Dale was involved in
 
−
all aspects of the experimental design and construction, and was the
 
−
lead on the design, construction, and testing of the pair spectrometer.
 
−
This pair spectrometer was successfully
 
−
commissioned
 
−
in 2002, and is now a part of the standard beamline instrumentation in
 
−
Hall B.
 
  
 
====Coherent Bremsstrahlung Facility====
 
====Coherent Bremsstrahlung Facility====
−
An instrumented collimator, having an aperture of 2.0 mm in diameter, is installed in the Hall-B beamline downstream of the tagger magnet
+
An instrumented collimator, having an aperture of 2.0 mm in diameter, is installed in the Hall-B beamline downstream of the tagger magnet and is located 22.9 m away from the diamond radiator. The collimator~\cite{collimator-cole}, designed and calibrated by CoPI Cole, forms part of the Coherent Bremstrahlung Facility; it serves to enhance the degree of linear polarization, $P$, within the coherent peak. As shown in Fig~\ref{fig:PriorNSFProducts}, the coherent distribution, peaked at 2.1~GeV, is considerably enhanced by tightly collimating the photon beam to one half of a characteristic angle. The spectra were taken with an electron beam energy of 4.5 GeV. Since the merit function  
−
and is located 22.9 m away from the diamond radiator. The collimator~\cite{collimator-cole}, designed and calibrated by CoPI Cole, forms part of the Coherent Bremstrahlung Facility; it serves to enhance the degree of linear polarization, $P$, within the coherent peak.
+
%scales as $1/P_{\gamma}^2$  
−
As shown in Fig~\ref{fig~cohpeak}, the coherent distribution, peaked at 2.1~GeV, is considerably enhanced by tightly collimating the photon
+
inversely scales with the photon poloarization squared,
−
beam to one half of a characteristic angle. The spectra were taken with an electron beam energy of 4.5 GeV. Since the merit function scales as $1/P_{\gamma}^2$ the collimation as shown in Fig.\ref{fig~cohpeak} enhances the quality of the polarization data by at least 30%.
+
the collimation as shown in Figure~\ref{fig:PriorNSFProducts} enhances the quality of the polarization data by at least 30\%.
  
−
=== Future Use of NSF funds===
 
  
−
The PI's in this proposal are spokepersons on experiments which require an energy upgraded JLAB and have undertaken the task of constructing the R1 drift chambers for Hall B. The future efforts will be towards completing the Qweak experiment, upgrading Hall B, and continue our efforts to increase underrepresented groups in physics from the Americas with the targeted dates shown in the timetable below.
+
====pair spectrometer====
 +
In 2000, an NSF MRI proposal (grant \# PHY-0079840) for \$970k was awarded (PIs: D.S.~Dale, A.~Gasparian, R.~Miskimen, S.~Dangoulian) for the construction of a multichannel neutral pion calorimeter, a pair spectrometer for flux monitoring, as well as a number of other pieces of experimental instrumentation for the {\em PrimEx} experiment. CoPI Dale was involved in all aspects of the experimental design and construction, and was the lead on the design, construction, and testing of the pair spectrometer. This pair spectrometer was successfully commissioned in 2002, and is now a part of the standard beamline instrumentation in Hall B.
  
−
==== Polarized Structure Functions====
+
==== Qweak Detector Construction====
−
<math>\frac{\Delta d}{d}</math>
+
The design, construction, and testing of the Region 1 tracking system for the $Q_{weak}$ experiment at Jefferson Lab has been the main research activity supported by PI Forest's previous NSF grant. The $Q_{weak}$ Region 1 tracking system is one of three tracking systems designed to measure the $Q^2$ profile of elastically scattered electrons as well as background contributions to the parity violating signal~\cite{Qweak}. The Region 1 tracking system is located behind the first collimator at a distance of about 550 cm from the main torus magnet (200 cm from the target). The high radiation flux and the small detector footprint are two of the biggest challenges facing the Region 1 tracking system. As a result, an ionization chamber equipped with Gas Electron Multipliers (GEM) was chosen in order to accommodate the high radiation flux near the target. The GEM preamplifiers allow smaller ionization cell sizes thereby resulting in ionization chamber rise times of 50 nanoseconds or less.
 +
Figure~\ref{fig:PriorNSFProducts} below shows the custom designed GEM detector for the $Q_{weak}$ Region 1 tracking system. Engineers from the Idaho Accelerator Center (IAC) designed the GEM preamplifiers. 
 +
This is a clear example of how the infrastructure at the IAC can be leveraged in support of our physics mission. The remaining detector design, machining, and assembly was completed using both graduate and undergraduate students.
  
−
\hspace{0.5in}Spin structure functions of the nucleon have been measured in deep inelastic (DIS)lepton scattering for nearly 30 years since the first
+
=== Future Use of NSF funds===
−
experiments at SLAC.  Interest increased substantially in the 80's when
 
−
the EMC collaboration reported that the
 
−
quark helicities made a small contribution to the overall
 
−
helicity of the proton, according to their data.  This ``spin
 
−
crisis'' led to a vigorous
 
−
theoretical and experimental 
 
−
effort over the next 20 years, with a large data set collected at CERN, SLAC, DESY and
 
−
Jefferson Lab.
 
−
As of today, the data
 
−
indicate that between 25\% - 35\% of the nucleon spin is carried
 
−
by the quark spins, with the remainder
 
−
being attributed to gluon polarization and orbital angular
 
−
momentum. The world data set however, has yet to resolve
 
−
whether the three valence quark spins ($uud$ in the
 
−
proton) follow the ``naive'' expectation
 
−
of relativistic quark models that 60\% -- 70\% of the nucleon spin is
 
−
carried by quark helicities.
 
−
 
 
−
The interest in this field continues unabated as new experiments
 
−
(COMPASS
 
−
%~\cite{COMPASS}
 
−
at CERN 
 
−
and the nucleon spin program at RHIC
 
−
%~\cite{RHIC}
 
−
) are attempting to measure
 
−
the low-$x$ gluon and sea quark
 
−
polarization in a polarized nucleon with high precision. At large-$x$, new
 
−
data from JLab address for the first time the question of the
 
−
helicity structure of the nucleon in a kinematic realm
 
−
where sea quark and gluon contributions are minimal thereby making
 
−
one mostly sensitive to valence quarks. Examples of these results
 
−
are shown in Fig.~\ref{delqJLab}.
 
−
To extend this region to higher $x$ and moderate
 
−
$Q^2$, one needs higher beam 
 
−
energies than presently available at JLab. In particular, to test
 
−
various models of the
 
−
asymptotic value of the virtual photon asymmetry $A_1(x)$ as $x
 
−
\rightarrow 1$, one needs
 
−
the upgraded CEBAF with 12 GeV beam energy.
 
  
 
\begin{figure} [!hbp]
 
\begin{figure} [!hbp]
 
\begin{center}{
 
\begin{center}{
−
\scalebox{0.4} [0.5]{\includegraphics{Graphs/delq_new1.eps}}
+
\scalebox{0.25} [0.35]{\includegraphics{Graphs/deltad_CLAS12.eps}}
−
\scalebox{0.4} [0.5]{\includegraphics{Graphs/deltad_CLAS12.eps}}
+
\scalebox{0.2} [0.3]{\includegraphics{Graphs/p11_high.eps}}
 
}
 
}
−
\caption{The polarized to unpolarized up and down quark
+
\caption{ The left figure represents a comparison between the measurement to be made
−
distribution ratio. The left figure shows the results
+
using an energy upgraded JLab with fits of the world data set for $\frac{\Delta d}{d}$.
−
from recent JLab experiments on the virtual photon asymmetry $A_1$ for
+
The expected data have been drawn along the pQCD and CQM prediction. The right figure  
−
the proton, Deuteron~\cite{EG2DeltaD} and neutron
+
represents the high $Q^2$ measurements that are possible after the upgrade to Hall B.
−
($^3$He)~\cite{HallADeltaD}.  The right figure represents the
+
Projected $N^*$ electrocoupling for the Roper $P_{11}(1440)$ as a function of $Q^{2}$ where
−
proposed measurements.  The expected data have been draw along
+
the open circles with error bars are from our expected experiment~\cite{NSTAR12}, the
−
the pQCD and CQM prediction. }  
+
closed squares are from the available CLAS data on single pion electroproduction~\cite{Aznauryan-2005},
−
\label{delqJLab}
+
and the solid blue squares are the preliminary data from analysis of e1-6 run
 +
overlaid with the results from the combined analysis of single and double pion
 +
electroproduction off protons~\cite{Aznauryan-2005-1}.}
 +
\label{fig:JLab12GeVPhysics}
 
\end{center}
 
\end{center}
 
\end{figure}
 
\end{figure}
 +
==== Work Plan====
  
 +
The work undertaken to satisfy the objectives for the funding cycle of this proposal involves the
 +
completion of the Region 1 tracking system for $Q_{weak}$ and the construction of drift chambers for the
 +
Hall B 12 GeV upgrade according to the milestones shown in Table~\ref{table:Timeline}. 
 +
The construction of the $Q_{weak}$ Region 1 tracking system detector will be completed before the
 +
current NSF funding cycle expires.  The R1 tracking system is expected to be delivered to JLab
 +
during the summer of 2009 and be integrated with other tracking system components to test the
 +
system before the scheduled installation in early 2010.  PI Forest will play a critical role
 +
integrating the detector and front end electronics into the rest of the tracking system during the
 +
first few months of this proposal as well as during the installation and operation of the system
 +
in the two years that follow.  During the same time frame, CoPIs Cole and Dale will be responsible
 +
for installing a clean room facility at ISU which will be used to construct drift chambers for
 +
JLab's Hall B starting in early 2010.  The class-10,000 clean room for this project has been designed in collaboration with JLab's drift chamber management group and bids have been received.  The drift chamber construction for Hall B is
 +
a critical component in support of the 12 GeV upgrade program at JLab and will
 +
support the ISU physics program.
  
−
The comprehensive data set to be
+
 
−
collected by experiment PR12-06-109 will contribute
+
\begin{table}[h]
 +
\begin{center}
 +
\begin{tabular}{ll}
 +
\multicolumn{1}{r}{Date}&
 +
\multicolumn{1}{c}{Objective}\\
 +
\hline\hline
 +
06/09 & Begin installing a clean room for constructing Hall B R1 Drift Chambers \\
 +
& at the Idaho Accelerator Center \\
 +
09/09 & Complete testing of the $Q_{weak}$ Region 1 tracking system at JLab \\
 +
01/10 & Begin Construction of R1 Chambers \\
 +
03/10 & Complete installation of  $Q_{weak}$ Region 1 tracking system in JLab's Hall C \\
 +
06/10 & Quality Assurance Tests for the First R1 Drift Chambers \\
 +
10/12 & Install all R1 chambers in Hall-B \\
 +
08/09 - 07/11 & Continue efforts with the Americas \\
 +
% & in Latin America through the Latin American Symposia for \\
 +
% & Nuclear Physics and Applications and further recruit students \\
 +
% & into areas of research involving JLab physics. \\
 +
08/09 - 07/11 & Analyze g8b and g13a/b data:  omega and charged rho production.  \\
 +
\hline
 +
\end{tabular}
 +
\end{center}
 +
\caption{Work Plan Timeline}
 +
\label{table:Timeline}
 +
\end{table}
 +
 
 +
====ISU's 12 GeV Physics Program====
 +
 
 +
The ISU group is currently the spokespersons on two experiments proposed for a 12 GeV upgraded Hall B. 
 +
The first experiment, PR12-06-109, will make measurements that contribute
 
substantially to our knowledge of polarized parton distribution
 
substantially to our knowledge of polarized parton distribution
 
functions for all quark flavors and even the polarized  
 
functions for all quark flavors and even the polarized  
−
gluon distribution $\Delta g$. Through Next-to-Leading Order (NLO) analysis
+
gluon distribution $\Delta g$. One particular outcome, shown in Figure~\ref{fig:JLab12GeVPhysics},  
−
of the world data on inclusive DIS (using the DGLAP
+
will improve our ability to test the high-x prediction made by pQCD and the constituent quark model.
−
evolution equations), one can constrain these
+
While pQCD predicts that $\frac{\Delta d}{d}$ should go to unity at $x_{bjk} =1$,
−
distribution functions and their integrals. Existing CLAS data
+
the constituent quark model, with hyperfine interactions, predicts a value closer to $-$1/3. A second
−
from 6 GeV have already made an impact on these fits. The
+
component to ISU's 12 GeV program will seek to measure the exclusive
−
expected data from the proposed experiment at 11 GeV will yield
 
−
further dramatic reductions in the errors on these distributions.
 
−
In addition, semi-inclusive DIS (SIDIS)
 
−
data will also be collected, where in addition
 
−
to the scattered electron we will detect some of the leading
 
−
hadrons produced when
 
−
the struck quark hadronizes. These data will further constrain
 
−
the NLO fits and improve the
 
−
separation of the various quark flavors' contribution to the nucleon spin.
 
−
 
 
−
==== Baryon Spectroscopy Program====
 
−
In January 2009, we will submit the proposal {\it Nucleon Resonance Studies
 
−
with CLAS12 in the Transition from Soft to Partonic Physics}~\cite{NSTAR12}.
 
−
In the effort to extract baryon resonances, we seek to measure the exclusive
 
 
single- and double-pion channels
 
single- and double-pion channels
−
produced through 11-GeV electrons directed onto a proton target
+
produced when 11-GeV electrons are directed onto a proton target with an upgraded CLAS detector.
−
within the upgraded CLAS detector.
+
The goal will be to perform measurements of resonances, like the  
−
We will extract the transition amplitudes first for well-established
+
$P_{11}(1440)$ resonance shown in Figure~\ref{fig:JLab12GeVPhysics}, which will be used as input
−
baryon resonances and then lesser known N*s in the unexplored
+
to models describing such transitions.  The Excited Baryon Analysis Center (EBAC) at JLab is one such
−
$Q^2$ range 4 to 14~GeV$^{2}$.
+
effort which will use an advanced coupled-channel approach in these fits.  These studies will
−
These transition amplitudes will be extracted in fits to all combined
 
−
channels -- but neglecting their mutual couplings --
 
−
using both differential cross sections and polarization
 
−
observables spanning the full angular range in azimuth and polar angle.
 
−
Such successful fits to all
 
−
observables on the transition amplitudes will provide initial inputs
 
−
to an advanced coupled-channel approach, which will be lead by the
 
−
Excited Baryon Analysis Center (EBAC) at JLab.  From this two-step process,
 
−
we expect to extract reliable and accurate resonant transition amplitudes.
 
−
These studies will
 
 
afford us the means to sample the transition from the hadronic
 
afford us the means to sample the transition from the hadronic
 
to partonic regime.
 
to partonic regime.
−
Indeed, the {\it Electromagnetic N-N* Transition Form Factors Workshop}
 
−
(Oct 11-13, 2008) was convened to bring theorists and experimentalists
 
−
together to establish new collaborations and strengthen this very proposal.
 
−
 
−
==== CLAS 12 DC Design and Construction ====
 
−
 
−
The ISU physics group is currently planning to built the Region 1 drift chambers at ISU for the Hall-B 12 GeV upgrade.  Three sets of azimuthally-symmetric wire chambers form the CLAS12 forward-tracking system and will have the same apt naming convention: Region 1, 2 and 3 (or R1, R2, & R3, respectively).    The primary design objective is to achieve nearly full acceptance, in the lab frame, for relativistic forward-boosted final-state particles while maintaining a momentum resolution of 0.5 to 1% for a 5 GeV/c charged particle.  In this document we shall focus on Region 1. Six identical R1 DCs will located 2.3 meters from the target and together will have a 2<math>\pi</math> azimuthal coverage and presently span from 5 to 45 degrees in polar angle as measured from the direction of the electron beam. The central plane through the R1 DC will be tilted 25 degrees from a perpendicular to the beam line towards the target. 
 
−
 
−
[[Image:CLAS12_ForwardDetector.png]][[Image:CLAS12_ForwardDetector_EPS.eps]]
 
−
 
−
A clean room has been designed for the purpose of constructing the R1 chambers at the IAC.  A 20' by 30' by 14' high softwall clean room will be installed at the IAC which maintains at positive pressure to reduce drift chamber contaminants.  An ante chamber (dimensions: 12' x 20' x 14' high) will exist along the width of the main room and will bepartitioned into two parts.  One part is the dressing room and the other part will be a staging area for bringing the 8' by 8' wire chambers in and out .  The curtains will be clear 40-mil thick vinyl.  We require good lighting for threading the 30 μm wire into the feedthrough holes and a sufficient number of fan-filter units to maintain the Class 10,000 (ISO 7) designation, which requires an exchange of 30 air volumes per hour.  The ceiling will have removable tiling, with one aluminum panel having a 2'' diameter grommet to allow for a cable from the 5-ton crane overhead to enter the cleanroom.  We calculate that a fully-loaded R1 DC with assembly carriage will weigh less than a ton.  We expect to procure and install the clean room by the summer of 2009.
 
−
 
−
==== Work Plan====
 
−
 
−
A work plan time line is given below which summarizes the objectives of this proposal.
 
−
 
−
 
−
{| border="1"  |cellpadding="20" cellspacing="0
 
−
|-
 
−
|Date|| Milestones
 
−
|-
 
−
|06/09 || Begin installing a clean room for constructing Hall B R1 Drift Chambers at the Idaho Accelerator Center
 
−
|-
 
−
|09/09 || Complete testing of the Qweak Region 1 tracking system at JLab
 
−
|-
 
−
|01/10 || Begin Construction of CLAS12 R1 Chambers
 
−
|-
 
−
|03/10 || Complete installation of  Qweak Region 1 tracking system in JLab's Hall C
 
−
|-
 
−
|06/10 || Quality Assurance Tests for the First R1 Drift Chambers
 
−
|-
 
−
|10/12 || Install all R1 chambers in Hall-B
 
−
|-
 
−
|08/09 - 07/11 || Continue efforts in establishing collaborations with nuclear physicists in Latin America through the Latin American Symposia for Nuclear Physics and Applications and further recruit students into areas of research involving JLab physics.
 
−
|-
 
−
|08/09 - 07/11 || Analyze g8b and g13a/b data:  omega and charged rho production. 
 
−
|}
 
  
 
====List of Currently supported students====
 
====List of Currently supported students====
Line 907: Line 575:
 
| Adrianne Spilker || M.S. ||2009
 
| Adrianne Spilker || M.S. ||2009
 
|-
 
|-
−
|Saitiniyazi Shadike || M.S.  || 2009
+
|Shadike Saitiniyazi || M.S.  || 2009
 
|-
 
|-
−
|Jordan Keonough || BS  || 2011
+
|Jordan Keough || BS  || 2011
 
|-
 
|-
 
|Nathan Lebaron|| BS  || 2012
 
|Nathan Lebaron|| BS  || 2012
 
|}
 
|}
 +
 +
==The Broader Impact of the Idaho State University Nuclear Physics Research Program}\label{section:BroaderImpacts}
 +
\subsection{The Americas}==
 +
 +
 +
Our broader impacts activities are directed
 +
towards the Americas, central and south. 
 +
Over the past nine years, the two CoPIs have
 +
have been active in outreach towards Latin America. 
 +
CoPIs Dale and Cole can both communicate in Spanish.  Indeed,
 +
this past year CoPI Cole
 +
successfully completed Spanish 201 and 202 at ISU, as a Freshman
 +
with an undeclared major, and he is presently enrolled in an advanced
 +
Spanish composition course at the 300-level in the effort to attain fluency.
 +
Speaking Spanish is necessary for our broader impacts activities.
 +
South American physics students tend to read English
 +
rather well, but speaking good 
 +
English is entirely another matter.  To attract students,
 +
one needs to present the many
 +
research opportunities in medium energy nuclear physics in the United States while
 +
dispelling subtle and not-so-subtle misconceptions, which abound. 
 +
And to communicate these matters, it is imperative to speak good Spanish. 
 +
 +
We seek to promote dialogue between faculty members of North-American and
 +
Latin-American institutions by finding common interests in research which
 +
will allow for coordinating our programs in nuclear physics research.
 +
Through this effort, we  expect to strengthen existing links and forge
 +
new ones within the broad scope of the international nuclear physics
 +
community. CoPI Cole has been a PI four times and a CoPI  twice on six separate
 +
Americas Program grants, which amounts in \$130k in funding.
 +
 +
 +
 +
\medskip
 +
\begin{center}
 +
\underline{\sf Funding History}
 +
\end{center}
 +
 +
\begin{itemize}
 +
\item The {\sf III Latin American Workshop on Nuclear and Heavy Ion Physics}
 +
(PI: Phil Cole) NSF-INT-9907453 for \$15,000
 +
 +
\item {\sf A Collaborative Effort between the U.S. and Colombia on the Physics
 +
with Linearly Polarized Photons}. (PI: Phil Cole) NSF-OISE-0101815 for \$32,590.
 +
 +
\item {\sf Americas Program: Student Sponsorship at the Fourth Latin
 +
American Symposium on Nuclear Physics, Mexico City, Mexico, September 24-28,
 +
2001.}  (PI: Phil Cole)
 +
NSF-OISE-0117545  for \$23,369
 +
 +
 +
\item {\sf US-Brazil Student Sponsorship at the Fifth Latin American Symposium on Nuclear Physics; Santos, Brazil, September 1-5, 2003}
 +
(PI: Phil Cole, CoPI Jorge Lopez) NSF-OISE-0313656  for \$18,000
 +
 +
\item {\sf U.S.-Argentina Collaborative Workshop in Nuclear Physics
 +
and Its Applications} (PI: Chaden Djalali, CoPI: Phil Cole) NSF-OISE-0527110
 +
for \$32,200.
 +
 +
\item {\sf US-Peru Workshop in Nuclear Physics and Its Applications,
 +
June 11-16, 2007, Cusco, Peru} (PI: Chaden Djalali, CoPI: Phil Cole)
 +
NSF-OISE-0652360 for \$32,200.  See:  VII Latin American Symposium on
 +
Nuclear Physics and Applications, AIP Conference Proceedings 947 (2007),
 +
Editors: Ricardo Alarcon, Philip L.~Cole, Chaden Djalali, and Fernando Umeres.
 +
 +
\end{itemize}
 +
 +
Recent outcomes of our links with the Latin American community
 +
include Mr. Tulio Rodrigues' visit to Jefferson Lab in August 2004 to work
 +
with CoPI Dan Dale
 +
on theoretical calculations for the {\em PrimEx} experiment.  At the time
 +
CoPI Dale was at the University of Kentucky.
 +
Mr.~Rodrigues was supervised by Dr.~Arruda-Neto, head of the Nuclear Reactions
 +
and Structure Research Group at the Physics Institute of the University of
 +
S\~{a}o Paulo and received his Ph.D. in 2006.  Dr.~Rodrigues has visited ISU
 +
twice in the past two years to work on {\em PrimEx}-related physics.
 +
Another graduate student, Mr.~Vladimir Montealegre from the
 +
Universidad de los Andes in Bogot\'{a}, Colombia, entered the Ph.D. program
 +
at the University of South Carolina. 
 +
Our recruitment efforts are paying off. 
 +
Our group now has two strong Ph.D. students, Juli\'{a}n Salamaca and Danny
 +
Mart\'{\i}nez, from Colombia and upon processing the necessary paperwork,
 +
two more Ph.D. students from Colombia will join us in January, 2009. 
 +
 +
 +
\medskip
 +
\begin{center}
 +
\underline{\sf The Need}
 +
\end{center}
 +
 +
Lack of modern equipment is one of the main obstacles to research
 +
in the less-developed Latin American countries.  There is, however,
 +
considerable variation in the size and influence of the physics community by
 +
individual countries~\cite{MoranLopez}.
 +
A few groups have managed to pursue successful
 +
experimental programs in countries with comparatively long traditions in
 +
applied and basic research in the nuclear sciences; the chief examples
 +
being Argentina, Brazil, Chile, and Mexico, countries where research is
 +
fostered through collaborative efforts through annual national nuclear
 +
physics conferences. Two of these countries  Brazil, site of the V LASNP,
 +
and Argentina, site of the VI LASNPA,  have launched initiatives to
 +
construct large facilities allowing for their use by the wider international
 +
nuclear physics community: the Brazilian National Synchrotron Light Laboratory
 +
(LNLS) in Campinas (about 70 miles west of S\~{a}o Paulo) and the Tandar heavy
 +
ion accelerator in Buenos Aires, Argentina.  Other countries in the region
 +
which have recently initiated activities aimed to improve their academic and
 +
scientific infrastructure in the nuclear sciences include Bolivia, Colombia,
 +
Peru and Venezuela. 
 +
 +
\medskip
 +
\begin{center}
 +
\underline{\sf The Opportunity}
 +
\end{center}
 +
 +
There is ample room for collaborative overlap between the two hemispheres.
 +
Establishing links between the United States and Latin America will provide a
 +
means for recruiting high-caliber graduate-level students and post-doctoral
 +
fellows to pursue research at US institutions and laboratories such as JLab,
 +
RHIC, ORNL, RIA, and IAC.  Such an academic relationship between North and
 +
South America will further strengthen the scientific endeavors of the nuclear
 +
physics communities of both continents. There is at present a dearth of
 +
graduate students pursuing advanced degrees in experimental and theoretical
 +
nuclear physics at US universities. This shortage is keenly felt at the
 +
national laboratories and facilities, where there is an abundance of Ph.D.
 +
theses topics and a paucity of graduate students. 
 +
The goal is to build
 +
ties with faculty and students. While attracting students to US graduate
 +
programs, we also wish to build new groups and infrastructure in Latin
 +
America that would give the students an attractive career option in their
 +
home country after graduation.
 +
 +
%\newpage
 +
%\medskip
 +
\begin{center}
 +
\underline{\sf The Means and the Goals}
 +
\end{center}
 +
 +
We seek to grow these outreach efforts and our group
 +
will continue to write funding grants to the NSF Americas Program
 +
for sponsoring students to attend future interactions of the Latin
 +
American Symposium for Nuclear Physics and Applications.  CoPI Cole
 +
was recently elected to the ten-member board International Organizing Committee
 +
of the VIII Latin American Symposium on Nuclear Physics and Applications
 +
to be held in Santiago, Chile, December 15-19, 2009.  As in the past,
 +
the Committee's
 +
responsibilities include the scientific program, formation of an
 +
International Advisory Board, and some key aspects of the overall
 +
organization of the Symposium.  Of this membership, three members are
 +
from Universities in the United States.  With a colleague in Argentina, CoPI Cole further will
 +
write a grant to the International Atomic Energy Agency to help defray
 +
travel expenses for non-U.S.~students in Latin America, where typically
 +
funding from the NSF cannot be obtained.
 +
 +
\subsection{Graduate Student Training and Marketability}
 +
 +
\hspace{0.5in} The role graduate students play in the experiments which take place within
 +
our program provide them with marketable skill sets.  Maria Novovic and Jena Kraft are clear
 +
examples of the impact members of this group have had training an underrepresented group in physics.
 +
Maria Novovic was trained in data acquisition, scintillator construction, and data analysis.
 +
She is currently a staff physicist at the University of Southern Alabama and is responsible for the
 +
undergraduate physics laboratories in addition to her undergraduate instructor role. The graduate
 +
training and experiences in PI Forest's lab were instrumental in securing her current position.
 +
Jena Kraft, who found a position in industry, reported that her design skills acquired while making a high pressure gas chamber for the GEM detector during her thesis were a key ingredient to her current position. The detector construction and instrumentation projects described in this proposal will continue to be effective in training graduate students for the market place.
 +
The Intermediate Energy Nuclear Physics Group at Idaho State University currently has three graduate students, listed in Table~\ref{table:Students}, working on JLab physics.  Our expectation is that this number will increase with the addition of two faculty with JLab projects and the annual influx of more than 10 incoming graduate students per year.
 +
  
 
==Facilities==
 
==Facilities==

Revision as of 00:01, 24 September 2008

NSF Proposal Guide

d. Project Description (including Results from Prior NSF Support)

(i) Content

All proposals to NSF will be reviewed utilizing the two merit review criteria described in greater length in GPG Chapter III.

The Project Description should provide a clear statement of the work to be undertaken and must include: objectives for the period of the proposed work and expected significance; relation to longer-term goals of the PI's project; and relation to the present state of knowledge in the field, to work in progress by the PI under other support and to work in progress elsewhere.

The Project Description should outline the general plan of work, including the broad design of activities to be undertaken, and, where appropriate, provide a clear description of experimental methods and procedures and plans for preservation, documentation, and sharing of data, samples, physical collections, curriculum materials and other related research and education products. It must describe as an integral part of the narrative, the broader impacts resulting from the proposed activities, addressing one or more of the following as appropriate for the project: how the project will integrate research and education by advancing discovery and understanding while at the same time promoting teaching, training, and learning; ways in which the proposed activity will broaden the participation of underrepresented groups (e.g., gender, ethnicity, disability, geographic, etc.); how the project will enhance the infrastructure for research and/or education, such as facilities, instrumentation, networks, and partnerships; how the results of the project will be disseminated broadly to enhance scientific and technological understanding; and potential benefits of the proposed activity to society at large.

Project Summary

\begin{flushright} \today \end{flushright}

\centerline{{\bf Project Summary}: Experimental Nuclear Physics at Jefferson Lab}

\centerline{{\bf PIs}: Tony Forest, Phil Cole, and Dan Dale}


This proposal requests support for a program using electromagnetic probes to study hadronic matter on a fundamental level at the Thomas Jefferson National Accelerator Facility. Although the group recently formed at Idaho State Univeristy, each of the senior level participants has a history of intense involvement in the Jefferson Lab physics program. We are requesting support from the NSF to allow our graduate students to complete their Ph.D. degrees with our current physics program and facilitate the construction of equipment for the 12 GeV JLab upgrade.

Intellectual Merit

\begin{center} {\it \underline {The Intellectual Merit of the Proposed Activities}} \end{center}


Our group is currently focused on three fundamental experiments. The $Q_{weak}$ experiment will utilize parity violating electron scattering to measure the weak mixing angle, $sin^2(\theta_w)$. This measurement represents a stringent test of the Standard Model or alternatively, a search for new physics beyond the Standard Model. Led by Dr. Tony Forest, Idaho State University's contribution to the $Q_{weak}$ program includes a major instrumentation component, namely, the Region 1 Detector and the Front End electronics. Dr. Philip Cole is focusing on comprehensive measurements of vector meson and hyperon photoproduction utilizing linearly polarized photons to improve our understanding of the underlying symmetry of the quark degrees of freedom in the nucleon, the nature of the parity exchange between the incident photon and the target nucleon, and the mechanism of associated strangeness production in electromagnetic reactions. Dr. Dan Dale is a spokesperson for the {\em PrimEx} Collaboration which seeks to perform a high precision measurement of the neutral pion lifetime as a test of the chiral anomaly in QCD, along with different approaches to corrections to the anomaly. Using photoproduction in the Coulomb field of a nucleus, this measurement will provide a stringent test of the predictions of quantum chromodynamics in the confinement scale regime. With a view toward the future upgrade of the Jefferson Lab accelerator, the Idaho State University group is proposing to built the Region 1 drift chambers at ISU for the Hall-B 12 GeV program. Clean room facilities are currently being designed at Idaho State University for this effort.

Broader Impacts

\begin{center} {\it \underline {Broader Impacts of the Proposed Activities}} \end{center}


In addition to the scientific program described here, this proposal represents a major effort in the area of educating future scientists. The present shortage of graduate students in experimental and theoretical nuclear physics is having a detrimental impact on our national laboratories and facilities which posses a plethora of data but limited manpower for analyzing and disseminating the information. The Idaho State University Department of Physics is comprised of twelve tenure track faculty, all of whom have research interests which are in some way connected to nuclear physics and are in a position to directly address the shortage of graduate students. With its on campus accelerator and detector laboratories, the Department focuses on experimental and applied physics, giving students a strong ``hands oneducational experience. ISU's physics program is relatively new and rapidly growing. Last year, ISU physics faculty brought in approximately \$8 million in external research funds. Its Ph.D. program, begun in the Fall 0f 2005, presently has approximately 30 students with an additional 30 students pursuing research at the M.S. level.

The PI's are further strengthening our graduate program by making particular efforts to recruit high quality students from Latin America. Latin and South America are an untapped intellectual resource which can be a beneficial international partner in research and education. The Intermediate Energy Nuclear Physics Group has established a bridge for collaboration with Brazil and Argentina which during its short lifetime has brought five talented graduate students into nuclear physics. The activities within this proposal will provide another avenue through which the program can continue to solidify this mutually beneficial bridge of collaboration between the Americas.

Intellectual Merit of the Proposed Activity

A Program to Study Hadronic Matter using Electromagnetic Probes at JLab

We are requesting continuing NSF support for our established program studying hadronic matter using electromagnetic probes. This program currently supports three graduate students, who are in mid stride towards completing their Ph.D.s~in experimental nuclear physics. Even though the group was recently formed at Idaho State University, each of the senior-level participants have an established history of intense involvement in the Jefferson Lab physics program from their research at their former universities. The PIs, moreover, have a strong record of constructing scientific instrumentation with NSF funding and each has made substantial impacts to the field. The significance of our research and the objectives for the proposed work period are described in section~\ref{section:IntelectMerits}. Through our well established partnership with several universities in the Americas, we discuss in section~\ref{section:BroaderImpacts} our continued recruitment of underrepresented groups in physics. The requested funding will not only enable our graduate students to complete the JLab data analysis in a timely manner and obtain their Ph.D.~degrees, but these monies will further provide the necessary support to enable Idaho State University to construct the six inner drift chambers for the 12 GeV upgrade to Hall B of JLab; these tracking chambers being a critical-path item for the upgrade.

The ISU Physics Program

Q_{weak}

The $Q_{weak}$ experiment (E05-008), scheduled for installation in 2010, 

will use parity violating (PV)

electron-proton scattering at very low momentum transfers $(Q^2 \sim 0.03~ \rm{GeV}^2)$ to measure the weak mixing angle $\sin^2(\theta_W)$. The dominant contribution to the PV asymmetry measured by $Q_{weak}$ is given by the weak charge of the proton, $Q_W^p = 1-4\sin ^2 \theta _W$, with small corrections of order $Q^4$ from nucleon electromagnetic form factors. This measurement will be a standard model test of the running of the electroweak coupling constant, sin$^2$($\theta_W$). Any significant deviation of $\sin ^2 \theta _W$ from the standard model prediction at low $Q^2$ would be a signal of new physics, whereas agreement would place new and significant constraints on possible standard model extensions including new physics. A brief description of the physics behind the $Q_{weak}$ experiment and the crucial contributions of this proposal to the $Q_{weak}$ experiment are given below.

An essential prediction of the Standard Model is the variation of $\sin ^2 \theta _W$ with $Q^2$, often referred to as the ``running of $\sin ^2 \theta _W$. Testing this prediction requires a set of precision measurements at a variety of $Q^2$ points, with sufficiently small and well understood theoretical uncertainties associated with the extraction of $\sin ^2 \theta _W$. It also requires a careful evaluation of the radiative corrections to $\sin ^2 \theta _W$ in the context of the renormalization group evolution (RGE) of the gauge couplings. Such tests have been crucial in establishing QCD as the correct theory of strong interactions~\cite{Hin00}. The RGE evolution of the QED coupling has also been demonstrated experimentally~\cite{TOP97,VEN98,OPAL00,L300}. The gauge coupling of the weak interaction, however, represented at low energies by the weak mixing angle $\sin ^2 \theta _W$, has not yet been studied successfully in this respect.


Qweak s2w Precision.jpgFile:Qweak s2w Precision.eps A-d Delta Prec.xfig.jpgFile:A-d Delta Prec.xfig.eps


\begin{figure}[htbp] %\vspace{-1in} \begin{center} { \scalebox{0.2} [0.2]{\includegraphics{Graphs/s2w_2004_4_new_2.eps}} \scalebox{0.25} [0.25]{\includegraphics{Graphs/A_d_Delta_Prec.xfig.eps}} } \caption{The dependence of $\sin^2 \theta_W$ as a function of $Q^2$ cast in the MS bar scheme of reference~\cite{Erler}. The solid line represents the Standard Model prediction. The results from four experiments (APV~\cite{APV}, $Q_W(e)$~\cite{E158}, $\nu$-DIS~\cite{NuTeV}, Z-pole~\cite{Zpole} are shown together with the expected precision from the $Q_{weak}$ experiment (Q$_W(p)$~\cite{Qweak}. Expected precision of an inelastic asymmetry measured in one week using the Q$_{weak}$ apparatus compared with the expected asymmetry for several values of the low energy constant $d_{\Delta}$. The rectangular box indicates both the Q$^2$ bin and the asymmetry uncertainty.} \label{fig:PVAsym} \end{center} \end{figure}

Figure~\ref{fig:PVAsym} shows the Standard Model prediction in a particular scheme~\cite{QweakAp} for $\sin ^2 \theta _W$ versus $Q^2$ along with existing and proposed world data. As seen in this Figure, the very precise measurements near the $Z^0$ pole merely set the overall magnitude of the curve; to test its shape one needs precise off-peak measurements. Presently, there are only three off-peak measurements of $\sin ^2 \theta _W$ which test the running at a significant level: one from APV~\cite{APV}, one from high energy neutrino-nucleus scattering~\cite{NuTeV}, and the recently completed SLAC experiment E-158(Q$_w$(e))~\cite{E158}. The measurement of $Q_W^p$ described here will be performed with smaller statistical and systematic errors and has a much cleaner theoretical interpretation than existing low $Q^2$ data. In addition, this measurement resides in the semi-leptonic sector, and is therefore complimentary to experiment E-158 at SLAC, which resides in the pure leptonic sector and has determined $\sin ^2 \theta _W$ from PV $\vec e e$ (Moller) scattering to roughly a factor of two less precision at low $Q^2$~\cite{E158}. The total statistical and systematic error anticipated on $Q_W^p$ from these measurements is around 4\%~\cite{Qweak}, corresponding to an uncertainty in $\sin ^2 \theta _W$ of $\pm$0.0007. This would establish the difference in radiative corrections between $\sin ^2 \theta _W (Q^2 \approx 0)$ and $\sin ^2 \theta _W (M_Z )$ as a 10 standard deviation effect.

\medskip \begin{center} \underline{\sf ISU's role in $Q_{weak}$} \end{center}

PI Forest is currently the work package manager of the Region 1 detector and front end electronics for $Q_{weak}$. The Region 1 tracking system detectors are being assembled and will be tested by the end of 2008. This proposal will support the installation of a front end electronics system from CERN to digitize the analog output of the detectors. PI Forest has been using his startup funds to develop the infrastructure needed to implement this system in $Q_{weak}$. A critical milestone in the work plan, outlined in Table~\ref{table:Timeline}, will be the testing of the integrated tracking system during the summer of 2009 at JLab in preparation for the installation of the system in early 2010. Support from this proposal will be used to complete the front end electronics installation and maintain the Region 1 tracking system during the calibration phase of the $Q_{weak}$ experiment currently scheduled to begin installation in JLab's Hall C in early 2010.

In addition to providing a key component to the $Q_{weak}$ tracking system, PI Forest has also outlined a week long experiment to measure $d_{\Delta}$ using the $Q_{weak}$ apparatus~\cite{Qweak} to a statistical precision of less than 0.1 ppm as shown in Figure~\ref{fig:PVAsym}~\cite{LOIdDelta}. This low energy constant $d_{\Delta}$ was discovered while evaluating the radiative corrections for the PV $N\rightarrow \Delta$ transition~\cite{Zhu012}. The authors in Ref.~\cite{Zhu012} used Siegert's theorem to show the presence of a non-vanishing PV asymmetry at $Q^2=0$ which is proportional to $d_{\Delta}$. A measurement of the PV asymmetry in the $N\rightarrow \Delta$ transition at the photon point, or at very low $Q^2$ would provide a direct measurement of the low energy constant $d_{\Delta}$.

The low energy constant $d_{\Delta}$ is a fundamental constant which has implications to other long standing physics questions. The same PV electric dipole matrix element which results in $d_{\Delta}$ also drives the asymmetry parameter ($\alpha_{\gamma}$) in radiative hyperon decays, e.g. $\Sigma ^+ \rightarrow p\gamma$. Although Hara's theorem~\cite{Hara64} predicts that the asymmetry parameter ($\alpha_{\gamma}(\Sigma ^+ \rightarrow p\gamma$)) should vanish in the exact SU(3) limit, the Particle Data Group~\cite{PDGAlphaSigma} reports a measured value of $\alpha_{\gamma}(\Sigma ^+ \rightarrow p\gamma) = -$0.72$\pm$ 0.08. While typical SU(3) breaking effects are of order $(m_s - m_u )/1$GeV $\sim$ 15\%, the above asymmetry parameter is experimentally found to be more than four times larger. A solution proposed by the authors of Ref.~\cite{Bor99} involves including high mass intermediate state resonances $(1/2 ^- )$, where the weak Lagrangian allows the coupling of both the hyperon and daughter nucleon to the intermediate state resonances, driving the asymmetry parameter to large negative values. This same reaction mechanism was also shown to simultaneously reproduce the $s$- and $p$-wave amplitudes in non-leptonic hyperon decays, which has also been a long standing puzzle in hyperon decay physics. If the same underlying dynamics is present in the non-strange sector ($\Delta S = 0$) as in the strangeness changing sector ($\Delta S = 1$), one would expect $d_{\Delta}$ to be enhanced over its natural scale ($g_{\pi}$ = 3.8$\times 10^{-8}$, corresponding to the scale of charged current hadronic PV effects~\cite{Des80,Zhu00}). The authors of Ref.~\cite{Zhu012} estimate that this enhancement may be as large as a factor of 100, corresponding to an asymmetry of $\sim$ 4 ppm. This is comparable to the size of the effects due to the axial response and therefore easily measurable. Thus, a measurement of this quantity could provide a window into the underlying dynamics of the unexpectedly large QCD symmetry breaking effects seen in hyperon decays.


Vector Meson and Hyperon Photoproduction with Linearly Polarized Photons

The probe afforded by a beam of linearly-polarized photons allows one to gain access to several observables in photonucleon reactions, which otherwise would not be measurable. The polarization axis defines a unique direction in space whereby the angular distributions of the final-state particles can be uniquely referenced. The polarization axis of the photon beam breaks the azimuthal symmetry of the reaction, thereby introducing an azimuthal ($\Phi$) dependence to the differential cross section. This additional information on the angular dependence opens the door to the measurement of a host of observables which are accessible only with a beam of linearly-polarized photons; consequently it provides important constraints on the nature of the photon-nucleon reaction. Such polarization observables are necessary for extracting the spin/parity of the broadly overlapping baryon resonances and measuring such parameters over a large energy range with full angular coverage is crucial for disentangling such contributions. CoPI Cole is the contact person of the experiments which comprise the g8 run~\cite{Cole94,Ted98,FKlein99,Sanabria01,Pasyukg8,g8papers}. The scientific purpose of g8 is to improve the understanding of the underlying symmetry of the quark degrees of freedom in the nucleon, the nature of the parity exchange between the incident photon and the target nucleon, and the mechanism of associated strangeness production in electromagnetic reactions. With the high-quality beam of the tagged and collimated linearly-polarized photons and the nearly complete angular coverage of the Hall-B spectrometer, we seek to extract the differential cross sections and polarization observables for the photoproduction of vector mesons and kaons at photon energies ranging between 1.10 and 2.20~GeV.

In preparation for the g8a run, we commissioned the Coherent Bremsstrahlung Facility, which was essentially a new beamline in Hall B for producing a tagged and collimated beam of linearly polarized photons, where the mean polarization in the energy range of 1.8 to 2.2~GeV was 71\%. We enjoyed a reasonably successful two-month run for g8a, which so far, has culminated in two Ph.D. theses~\cite{CGordon, JMelone}, two master's theses~\cite{APuga, JSalamanca}, and one of the two NSF graduate research fellowships~\cite{RMammei} awarded in nuclear physics in 2003. We seek to build upon our earlier work and investigate the nature of resonant baryon states by probing protons with polarized photons. The set of experiments forming the first phase of the g8 run took place in the summer of 2001 (6/04/01 - 8/13/01) in Hall B of Jefferson Lab. These experiments made use of a beam of linearly-polarized photons produced through coherent bremsstrahlung and represents the first time such a probe was employed at Jefferson Lab. The second time this probe was used took place in the summer of 2005 (6/20/05 - 9/01/05) for the second phase of g8 (g8b), followed by g13b (3/08/07 - 6/29/07) and g9a (10/17/07 - 2/11/08). The g8 set of experiments, therefore, was a vital first step for establishing the Coherent Bremsstrahlung Facility and this experience paved the way for the successful runs with linearly polarized photons in Hall B of JLab: g13b ($\vec{\gamma}d$), and g9a ($\vec{\gamma}\vec{p}$). The lessons learned in calibration and cooking for g8b have accelerated the analyses for the g13a/b and g9a. And in the three years since the end of the g8b run, we have or are near completion of three Ph.D. theses: a) Craig Paterson~\cite{Paterson-g8b}, University of Glasgow, $\vec{\gamma}p \rightarrow K\Lambda, K\Sigma^{\circ}$, Aug.~2008), b) Patrick Collins~\cite{Collins-g8b}, Arizona State University, $ \vec{\gamma}p \rightarrow p\eta, p\eta^{\prime}$, Nov.~2008, and c) Juli\'{a}n Salamanca~\cite{Salamanca-g8b,LASNPA-7}, Idaho State University, $\vec{\gamma}p \rightarrow p\phi$, May~2009. \\

\noindent \underline{\bf Photoproduction of the $\phi(1020)$} \\ Vector meson photoproduction at high energies, as is well known, proceeds primarily through pomeron exchange rather than by $\pi$ or $\eta$ meson exchange, which are respectively termed natural and unnatural parity exchange. In the baryon resonance energy regime ($E_{\vec{\gamma}}\sim 2.0$ GeV) and at low four-momentum transfer squared, $t$, the peak structure of the coherent $\phi$-meson photoproduction cross section is not well explained at threshold by a pure pomeron-exchange-based model~\cite{mibe}. The extraction of the Spin Density Matrix Elements (SDMEs) from $\phi$-meson decay angular distributions will shed light on the proportion of natural and unnatural parity exchange involved in the reaction mechanism~\cite{shilling} at low $t$, which is further to be compared to the predicted values of the Vector Dominance Model (VDM)~\cite{sakurai}. We have several thousand $\phi$s mesons at both low and high $t$ in the baryon resonance regime of $2.02 < \sqrt{s} < 2.11$ GeV. With the exception of this g8 dataset, there are no photoproduced phi mesons with linearly polarized photons measured in the central region in the world data set. Extracting the SDMEs for the phi channel at high $|t|$ will therefore hold discovery potential for non-VDM mechanisms at higher four-momentum transfers squared. After making the necessary momentum, timing, particle ID, and Dalitz mass cuts we separate the data into unpolarized (AMO), perpendicular (PERP) polarization, and parallel (PARA) polarization. We fit a Breit-Wigner to the phi meson peak constrained with a decay width $\Gamma$ of 4.26~GeV with a second-order polynomial for fitting the background and a gaussian for representing the detector uncertainties. Below we display the phi peak obtained from extracting the $K^-$ from missing mass and then forming the invariant mass of the $K^+K^-$ separated in PERP and PARA orientations for the cms energy of $2.11 < \sqrt{s} < 2.20$~GeV.

File:Phi mass para perp.eps

\begin{figure}[h!] \begin{center} \includegraphics[height=.18\textheight]{Graphs/Cole_phi_mass_para_perp.eps} \caption{\small $K^+K^-$ invariant mass in the cms energy range of $2.11 < \sqrt{s} < 2.20$~GeV fit with a Breit-Wigner + Gaussian + 2nd order polynomial. The decay width is fixed at 4.26~GeV. (RHS) parallel (LHS) perpendicular polarizations.} \label{fig:phi_mass} \end{center} \end{figure} Below we plot the combination of parallel (PARA) and perpendicular (PERP) photoproduced phi mesons for all $t$ to obtain the photon beam asymmetry parameter: \\ %\begin{equation} $$\Sigma = (W^{PARA} - W^{PERP})/(W^{PERP} + W^{PARA}).$$ %\end{equation} 

These values are consistent with what we would expect from the Vector Dominance Model. We are presently working on separating the data into low- and high-$|t|$ regimes, but are not prepared to show it until we have authorization from the CLAS collaboration.

File:Asym all.eps

\begin{figure}[h!] \begin{center} \includegraphics[height=.18\textheight]{Graphs/Cole_asym_all.eps} \caption{\small Beam asymmetry for the phi meson channel over the full range of $t$ for (a) $1.9 < E_{\gamma} < 2.1$~GeV and (b) $1.7 < E_{\gamma} <1.9$~GeV. The photon beam polarization is 75\%.} \label{fig:asym} \end{center} \end{figure}




Primakoff

CoPI Dale is a spokesperson for the {\em PrimEx} Collaboration. At present, the scientific goal of the Collaboration is to perform a high precision measurement of the neutral pion lifetime as a test of the chiral anomaly in QCD, along with different approaches to corrections to the anomaly.

The two-photon decay mode of the $\pi^{0}$ reveals one of the most profound symmetry issues in quantum chromodynamics, namely, the explicit breaking of a classical symmetry by the quantum fluctuations of the quark fields coupling to a gauge field~\cite{book}. This phenomenon, called anomalous symmetry breaking, is of pure quantum mechanical origin. The axial anomaly of interest to us involves the corresponding coupling of the quarks to photons~\cite{anomaly}. In the limit of exact isospin symmetry, the $\pi^{o}$ couples only to the isotriplet axial-vector current $\bar{q}I_3\gamma_\mu \gamma_5 q$, where $q=(u,\; d)$, and $I_3$ is the third isospin generator. In the limit of two quark flavors, the electromagnetic current is given by $\bar{q}(1/6+ I_3/2)\gamma_\mu q$. When coupling to the photon, the isosinglet and isotriplet components of the electromagnetic current lead to an anomaly that explicitly breaks the symmetry associated with the axial-vector current 

$\bar{q}\;I_3\;\gamma_\mu \gamma_5\;q$, and this in turn
directly affects the coupling of the $\pi^{o}$ to two photons. The conservation of the  axial U(1) current,

to which the $\eta'$ meson couples, as well as the $\bar{q} \frac{1}{2}\lambda_{8}\gamma_\mu \gamma_5 q$, to which the $\eta$ meson couples, are similarly affected by the electromagnetic field.

For vanishing quark masses, the anomaly leads to the predicted width of the $\pi^{o} \rightarrow \gamma \gamma$ decay: \begin{equation} \Gamma=M_{\pi}^{3}\frac{ \mid A_{\gamma \gamma} \mid^{2}}{64\pi}= 7.725 \pm 0.044 ~\rm{eV}, \end{equation} where the reduced amplitude is \begin{equation} A_{\gamma \gamma} =\frac{\alpha_{em}}{\pi F_{\pi}} = 2.513 \cdot 10^{-2} ~\rm{GeV}^{-1} \end{equation}

In this expression, there are no free parameters. Since the mass of the $\pi^0$ is the smallest in the hadron spectrum, higher order corrections to this prediction are small and can be calculated with sub-percent accuracy. The current experimental value is $7.84 \pm 0.56$ eV~\cite{PDB} and is in good agreement with the predicted value with the chiral limit amplitude. This number is an average of several experiments~\cite{PDB}. Even at the 7\% level quoted by the Particle Data Book~\cite{PDB}, the accuracy is not sufficient for a test of the new calculations which take the finite quark masses into account. The level of precision of $\simeq 1.4\%$, which is the goal of {\em PrimEx}, will satisfy these requirements. Stimulated by the {\em PrimEx} project, several new theoretical calculations have been published in recent years, and are shown in Figure~\ref{fig:theory}. The first two independent 

 calculations of the chiral corrections were performed in the

combined framework of chiral perturbation theory (ChPT) and the $1/N_c$ expansion up to ${\cal{O}}(p^6)$ and ${\cal{O}}(p^4\times 1/N_c)$ in the decay amplitude~\cite{Goity}~\cite{Mou02}. The $\eta'$ is explicitly included in the analysis as it plays as important a role as the $\eta$ in the mixing effects. It was found that the decay width is enhanced by about 4\% with respect to the value stated in equation (1). This enhancement is almost entirely due to the mixing effects. The result of this next-to-leading order analysis is $\Gamma_{\pi^0\to\gamma\gamma}=8.10~ {\rm eV}$ with an estimated uncertainty of less than 1\%. Another theoretical calculation based on QCD sum rules~\cite{Ioffe07}, also inspired by the {\em PrimEx} experiment, has recently been published with a theoretical uncertainty less than 1.5\%. Here, the only input parameter to the calculation is the $\eta$ width.


File:Pio width new theory prel result.eps

\begin{figure} \begin{center} %\begin{minipage}[t]{0.58\linewidth} \begin{minipage}[t]{0.38\linewidth} \scalebox{0.5} [0.55]{\includegraphics{Graphs/Pio_width_new_theory_prel_result.eps}} %\epsfig{file=Graphs/Pio_width_new_theory_prel_result.eps,width=\linewidth} \end{minipage}\hfill %\begin{minipage}[t]{0.38\linewidth} \begin{minipage}[t]{0.48\linewidth} \vspace*{-10cm}\caption{$\pi^{o} \rightarrow \gamma \gamma$ decay width in eV. The dashed horizontal line is the leading order prediction of the axial anomaly~\cite{book, anomaly}.The left hand side shaded band is the recent QCD sum rule prediction and the right hand side shaded band is the next-to-leading order chiral theory predictions. The experimental results with errors are for : (1)~the direct method~\cite{At85}; (2, 3, 4)~the Primakoff method~\cite{Br74,Bel70,Kr70}; (5)~the preliminary result from the first {\em PrimEx} data set; (6)~the expected error for the final goal of the {\em PrimEx} experiment, arbitrarily plotted to agree with the leading order prediction. prediction.\label{fig:theory}} \end{minipage} \label{fig:Primextheory} \end{center} \end{figure}



We are using quasi-monochromatic photons of energy 4.6-5.7~GeV from the Hall~B photon tagging facility to measure the absolute cross section of small angle $\pi^{o}$ photoproduction from the Coulomb field of complex nuclei. The invariant mass and angle of the pion are reconstructed by detecting the $\pi^{o}$ decay photons from the $\pi^{o} \rightarrow \gamma \gamma$ reaction. For unpolarized photons, the Primakoff cross section is given by: \begin{equation} \frac{d\sigma_P}{d\Omega}=\Gamma_{\gamma \gamma}\frac{8{\alpha}Z^2}{m^3}\frac{\beta^3{E^4}}{Q^4}|F_{e.m.}(Q)|^ 2 \sin^{2}\theta_{\pi} \end{equation} \noindent where $\Gamma_{\gamma \gamma}$ is the pion decay width, $Z$ is the atomic number, $m$, $\beta$, $\theta_{\pi}$ are the mass, velocity and production angle of the pion, $E$ is the energy of incoming photon, $Q$ is the momentum transfer to the nucleus, and $F_{e.m.}(Q)$ is the nuclear electromagnetic form factor, corrected for final state interactions of the outgoing pion. As the Primakoff effect is not the only mechanism for pion photoproduction at high energies, some care must be taken to isolate it from competing processes. In particular, the full cross section is given by: \begin{equation} \frac{d\sigma}{d\Omega_{\pi}} = \frac{d \sigma_P}{d\Omega} + \frac{d\sigma_C}{d \Omega} + \frac{d \sigma_I}{d\Omega}+ 2 \cdot \sqrt{\frac{d\sigma_{P}}{d\Omega} \cdot \frac{d\sigma_{C}}{d\Omega}} cos(\phi_1 + \phi_2) \end{equation} \noindent where the Primakoff cross section, $\frac{d \sigma_P}{d\Omega}$, is given by equation (4). The nuclear coherent cross section is given by: \begin{equation} \frac{d\sigma_C}{d \Omega} = C \cdot A^2 |F_N(Q)|^2 \sin^2\theta_{\pi} \end{equation} and the incoherent cross section is: \begin{equation} \frac{d \sigma_I}{d\Omega}=\xi A (1-G(Q)) \frac{d \sigma_H}{d\Omega} \end{equation} where $A$ is the nucleon number, $C \sin^2\theta_{\pi}$ is the square of the isospin and spin independent part of the neutral meson photoproduction amplitude on a single nucleon, $|F_N(Q)|$ is the form factor for the nuclear matter distribution in the nucleus, (corrected for final state interactions of the outgoing pion), $\xi$ is the absorption factor of the incoherently produced pions, $1-G(Q)$ is a factor which reduces the cross section at small momentum transfer due to the Pauli exclusion principle, and $\frac{d \sigma_H}{d\Omega}$ is the $\pi^o$ photoproduction cross section on a single nucleon. The relative phase between the Primakoff and nuclear coherent amplitudes without final state interactions is given by $\phi_1$, and the phase shift of the outgoing pion due to final state interactions is given by $\phi_2$. The angular dependence of the Primakoff signal is different from the background processes, allowing $\Gamma(\pi^0\rightarrow \gamma\gamma)$ to be extracted from a fit to the angular distribution of photo-produced $\pi^0$. Measurements of the nuclear effects at larger angles are necessary to determine the unknown parameters in the production mechanism and thus make an empirical determination of the nuclear contribution in the Primakoff peak region. Consequently, this experiment uses a $\pi^{o}$ detector with good angular resolution to eliminate nuclear coherent production, and good energy resolution in the decay photon detection will enable an invariant mass cut to suppress multi-photon backgrounds. %Image:Primex pb cross color.ps %\begin{figure} %\centerline{\epsfxsize=200pt \epsfbox[200 150 430 500]{pb_cross_color.ps}} %\vspace{1cm} %\caption{Angular behavior of the electromagnetic and nuclear %$\pi^o$ photoproduction cross sections for %$^{208}$Pb in the 6.0~GeV energy range. } %\label{fig3} %\end{figure}

We submitted our first proposal (E-99-014) to PAC15 in December of 1998. It was approved by PAC15 and reconfirmed in jeopardy review later by PAC22 with an ``A rating. An NSF MRI proposal for \$970k was awarded (PIs: D.S.~ Dale, A.~Gasparian, R.~Miskimen, S.~Dangoulian) for the construction of a multichannel neutral pion calorimeter. This was successfully designed, constructed, and commissioned over the period 2000-2004. The first experiment on two targets ($^{12}$C and $^{208}$Pb) was performed in 2004. A second run (E-08-023, spokespersons: D.~Dale, A.~Gasparian, M.~Ito, R.~Miskimen) was approved by PAC33 with an $A-$ rating for 20 days of running to reach the proposed goal of $\sim 1.4\%$ accuracy. While the CoPI of this funding proposal has been involved in all aspects of this program, he has taken primary responsibility for the flux normalization. This has involved the design, construction, and commissioning of the {\em PrimEx} pair spectrometer. In addition, along with his students, he has been responsible for the analysis of the resulting data. This has also included a high precision measurement of the absolute cross section of a well known QED process, pair production, to verify that the flux determination was correct. %To date, the CoPI has supervised to completion one Ph.D. student (A. Teymurazyan) and one M.S. student on this work. One more Ph.D. student (O. Kosinov) is currently working toward his degree.







Prior and Future use of NSF Funds

BremFacility.jpgPairSpectrometer NSF08.jpgQweak BottomDetector HVboard Cathode and Bolts 2.jpg


File:BremFacility.epsFile:PairSpectrometer NSF08.epsFile:AssembledQweakDetector.eps

Prior use of NSF funds

\begin{figure}[htbp] %\vspace{-1in} \begin{center} { \scalebox{0.2} [0.4]{\includegraphics{Graphs/Cole_BremHist.eps}} \scalebox{0.25} [0.25]{\includegraphics{Graphs/DalePairSpect.eps}} \scalebox{0.15} [0.15]{\includegraphics[angle=90]{Graphs/QweakAssembledDetector.eps}} } \caption{The histograms show the improvement to Hall B's linearly polarized photon beam using the collimator designed and calibrated by CoPI Cole. The middle picture shows the pair spectrometer system installed in Hall B by CoPI Dale and his collaborators. The right most picture is of an assembled GEM detector for $Q_{weak}$'s Region 1 tracking system designed, machined and assembled by PI Forest and his students at ISU. } \label{fig:PriorNSFProducts} \end{center} \end{figure}


The PIs in this proposal have a strong record of receiving external funding from the NSF and a history of effectively using those funds to make substantially contributions to the infrastructure of the nuclear physics program described in this proposal, as summarized in Figure~\ref{fig:PriorNSFProducts}. The bremsstrahlung facility in JLab's Hall-B is one example of CoPI Cole's efforts to enhance the capabilities of Hall B's photon physics program. CoPI Dale has used NSF funds to install a pair spectrometer facility in Hall B. The Region 1 tracking system for $Q_{weak}$ was constructed by PI Forest using NSF funds.


Coherent Bremsstrahlung Facility

An instrumented collimator, having an aperture of 2.0 mm in diameter, is installed in the Hall-B beamline downstream of the tagger magnet and is located 22.9 m away from the diamond radiator. The collimator~\cite{collimator-cole}, designed and calibrated by CoPI Cole, forms part of the Coherent Bremstrahlung Facility; it serves to enhance the degree of linear polarization, $P$, within the coherent peak. As shown in Fig~\ref{fig:PriorNSFProducts}, the coherent distribution, peaked at 2.1~GeV, is considerably enhanced by tightly collimating the photon beam to one half of a characteristic angle. The spectra were taken with an electron beam energy of 4.5 GeV. Since the merit function %scales as $1/P_{\gamma}^2$ inversely scales with the photon poloarization squared, the collimation as shown in Figure~\ref{fig:PriorNSFProducts} enhances the quality of the polarization data by at least 30\%.


pair spectrometer

In 2000, an NSF MRI proposal (grant \# PHY-0079840) for \$970k was awarded (PIs: D.S.~Dale, A.~Gasparian, R.~Miskimen, S.~Dangoulian) for the construction of a multichannel neutral pion calorimeter, a pair spectrometer for flux monitoring, as well as a number of other pieces of experimental instrumentation for the {\em PrimEx} experiment. CoPI Dale was involved in all aspects of the experimental design and construction, and was the lead on the design, construction, and testing of the pair spectrometer. This pair spectrometer was successfully commissioned in 2002, and is now a part of the standard beamline instrumentation in Hall B.

Qweak Detector Construction

The design, construction, and testing of the Region 1 tracking system for the $Q_{weak}$ experiment at Jefferson Lab has been the main research activity supported by PI Forest's previous NSF grant. The $Q_{weak}$ Region 1 tracking system is one of three tracking systems designed to measure the $Q^2$ profile of elastically scattered electrons as well as background contributions to the parity violating signal~\cite{Qweak}. The Region 1 tracking system is located behind the first collimator at a distance of about 550 cm from the main torus magnet (200 cm from the target). The high radiation flux and the small detector footprint are two of the biggest challenges facing the Region 1 tracking system. As a result, an ionization chamber equipped with Gas Electron Multipliers (GEM) was chosen in order to accommodate the high radiation flux near the target. The GEM preamplifiers allow smaller ionization cell sizes thereby resulting in ionization chamber rise times of 50 nanoseconds or less. Figure~\ref{fig:PriorNSFProducts} below shows the custom designed GEM detector for the $Q_{weak}$ Region 1 tracking system. Engineers from the Idaho Accelerator Center (IAC) designed the GEM preamplifiers. This is a clear example of how the infrastructure at the IAC can be leveraged in support of our physics mission. The remaining detector design, machining, and assembly was completed using both graduate and undergraduate students.

Future Use of NSF funds

\begin{figure} [!hbp] \begin{center}{ \scalebox{0.25} [0.35]{\includegraphics{Graphs/deltad_CLAS12.eps}} \scalebox{0.2} [0.3]{\includegraphics{Graphs/p11_high.eps}} } \caption{ The left figure represents a comparison between the measurement to be made using an energy upgraded JLab with fits of the world data set for $\frac{\Delta d}{d}$. The expected data have been drawn along the pQCD and CQM prediction. The right figure represents the high $Q^2$ measurements that are possible after the upgrade to Hall B. Projected $N^*$ electrocoupling for the Roper $P_{11}(1440)$ as a function of $Q^{2}$ where the open circles with error bars are from our expected experiment~\cite{NSTAR12}, the closed squares are from the available CLAS data on single pion electroproduction~\cite{Aznauryan-2005}, and the solid blue squares are the preliminary data from analysis of e1-6 run overlaid with the results from the combined analysis of single and double pion electroproduction off protons~\cite{Aznauryan-2005-1}.} \label{fig:JLab12GeVPhysics} \end{center} \end{figure}

Work Plan

The work undertaken to satisfy the objectives for the funding cycle of this proposal involves the completion of the Region 1 tracking system for $Q_{weak}$ and the construction of drift chambers for the Hall B 12 GeV upgrade according to the milestones shown in Table~\ref{table:Timeline}. The construction of the $Q_{weak}$ Region 1 tracking system detector will be completed before the current NSF funding cycle expires. The R1 tracking system is expected to be delivered to JLab during the summer of 2009 and be integrated with other tracking system components to test the system before the scheduled installation in early 2010. PI Forest will play a critical role integrating the detector and front end electronics into the rest of the tracking system during the first few months of this proposal as well as during the installation and operation of the system in the two years that follow. During the same time frame, CoPIs Cole and Dale will be responsible for installing a clean room facility at ISU which will be used to construct drift chambers for JLab's Hall B starting in early 2010. The class-10,000 clean room for this project has been designed in collaboration with JLab's drift chamber management group and bids have been received. The drift chamber construction for Hall B is a critical component in support of the 12 GeV upgrade program at JLab and will support the ISU physics program.


\begin{table}[h] \begin{center} \begin{tabular}{ll} \multicolumn{1}{r}{Date}& \multicolumn{1}{c}{Objective}\\ \hline\hline 06/09 & Begin installing a clean room for constructing Hall B R1 Drift Chambers \\ 

& at the Idaho Accelerator Center \\

09/09 & Complete testing of the $Q_{weak}$ Region 1 tracking system at JLab \\ 01/10 & Begin Construction of R1 Chambers \\ 03/10 & Complete installation of $Q_{weak}$ Region 1 tracking system in JLab's Hall C \\ 06/10 & Quality Assurance Tests for the First R1 Drift Chambers \\ 10/12 & Install all R1 chambers in Hall-B \\ 08/09 - 07/11 & Continue efforts with the Americas \\ % & in Latin America through the Latin American Symposia for \\ % & Nuclear Physics and Applications and further recruit students \\ % & into areas of research involving JLab physics. \\ 08/09 - 07/11 & Analyze g8b and g13a/b data: omega and charged rho production. \\ \hline \end{tabular} \end{center} \caption{Work Plan Timeline} \label{table:Timeline} \end{table}

ISU's 12 GeV Physics Program

The ISU group is currently the spokespersons on two experiments proposed for a 12 GeV upgraded Hall B. The first experiment, PR12-06-109, will make measurements that contribute substantially to our knowledge of polarized parton distribution functions for all quark flavors and even the polarized gluon distribution $\Delta g$. One particular outcome, shown in Figure~\ref{fig:JLab12GeVPhysics}, will improve our ability to test the high-x prediction made by pQCD and the constituent quark model. While pQCD predicts that $\frac{\Delta d}{d}$ should go to unity at $x_{bjk} =1$, the constituent quark model, with hyperfine interactions, predicts a value closer to $-$1/3. A second component to ISU's 12 GeV program will seek to measure the exclusive single- and double-pion channels produced when 11-GeV electrons are directed onto a proton target with an upgraded CLAS detector. The goal will be to perform measurements of resonances, like the $P_{11}(1440)$ resonance shown in Figure~\ref{fig:JLab12GeVPhysics}, which will be used as input to models describing such transitions. The Excited Baryon Analysis Center (EBAC) at JLab is one such effort which will use an advanced coupled-channel approach in these fits. These studies will afford us the means to sample the transition from the hadronic to partonic regime.

List of Currently supported students

Student Classification Expected Grad Yr
Julian Salamanca Ph. D. 2009
Tamar Didbarize Ph. D. 2010
Danny Martinez Ph. D. 2012
Oleksei Kosinov Ph. D. 2012
Adrianne Spilker M.S. 2009
Shadike Saitiniyazi M.S. 2009
Jordan Keough BS 2011
Nathan Lebaron BS 2012

==The Broader Impact of the Idaho State University Nuclear Physics Research Program}\label{section:BroaderImpacts} \subsection{The Americas}==


Our broader impacts activities are directed towards the Americas, central and south. Over the past nine years, the two CoPIs have have been active in outreach towards Latin America. CoPIs Dale and Cole can both communicate in Spanish. Indeed, this past year CoPI Cole successfully completed Spanish 201 and 202 at ISU, as a Freshman with an undeclared major, and he is presently enrolled in an advanced Spanish composition course at the 300-level in the effort to attain fluency. Speaking Spanish is necessary for our broader impacts activities. South American physics students tend to read English rather well, but speaking good English is entirely another matter. To attract students, one needs to present the many research opportunities in medium energy nuclear physics in the United States while dispelling subtle and not-so-subtle misconceptions, which abound. And to communicate these matters, it is imperative to speak good Spanish.

We seek to promote dialogue between faculty members of North-American and Latin-American institutions by finding common interests in research which will allow for coordinating our programs in nuclear physics research. Through this effort, we expect to strengthen existing links and forge new ones within the broad scope of the international nuclear physics community. CoPI Cole has been a PI four times and a CoPI twice on six separate Americas Program grants, which amounts in \$130k in funding.


\medskip \begin{center} \underline{\sf Funding History} \end{center}

\begin{itemize} \item The {\sf III Latin American Workshop on Nuclear and Heavy Ion Physics} (PI: Phil Cole) NSF-INT-9907453 for \$15,000

\item {\sf A Collaborative Effort between the U.S. and Colombia on the Physics with Linearly Polarized Photons}. (PI: Phil Cole) NSF-OISE-0101815 for \$32,590.

\item {\sf Americas Program: Student Sponsorship at the Fourth Latin American Symposium on Nuclear Physics, Mexico City, Mexico, September 24-28, 2001.} (PI: Phil Cole) NSF-OISE-0117545 for \$23,369


\item {\sf US-Brazil Student Sponsorship at the Fifth Latin American Symposium on Nuclear Physics; Santos, Brazil, September 1-5, 2003} (PI: Phil Cole, CoPI Jorge Lopez) NSF-OISE-0313656 for \$18,000

\item {\sf U.S.-Argentina Collaborative Workshop in Nuclear Physics and Its Applications} (PI: Chaden Djalali, CoPI: Phil Cole) NSF-OISE-0527110 for \$32,200.

\item {\sf US-Peru Workshop in Nuclear Physics and Its Applications, June 11-16, 2007, Cusco, Peru} (PI: Chaden Djalali, CoPI: Phil Cole) NSF-OISE-0652360 for \$32,200. See: VII Latin American Symposium on Nuclear Physics and Applications, AIP Conference Proceedings 947 (2007), Editors: Ricardo Alarcon, Philip L.~Cole, Chaden Djalali, and Fernando Umeres.

\end{itemize}

Recent outcomes of our links with the Latin American community include Mr. Tulio Rodrigues' visit to Jefferson Lab in August 2004 to work with CoPI Dan Dale on theoretical calculations for the {\em PrimEx} experiment. At the time CoPI Dale was at the University of Kentucky. Mr.~Rodrigues was supervised by Dr.~Arruda-Neto, head of the Nuclear Reactions and Structure Research Group at the Physics Institute of the University of S\~{a}o Paulo and received his Ph.D. in 2006. Dr.~Rodrigues has visited ISU twice in the past two years to work on {\em PrimEx}-related physics. Another graduate student, Mr.~Vladimir Montealegre from the Universidad de los Andes in Bogot\'{a}, Colombia, entered the Ph.D. program at the University of South Carolina. Our recruitment efforts are paying off. Our group now has two strong Ph.D. students, Juli\'{a}n Salamaca and Danny Mart\'{\i}nez, from Colombia and upon processing the necessary paperwork, two more Ph.D. students from Colombia will join us in January, 2009.


\medskip \begin{center} \underline{\sf The Need} \end{center}

Lack of modern equipment is one of the main obstacles to research in the less-developed Latin American countries. There is, however, considerable variation in the size and influence of the physics community by individual countries~\cite{MoranLopez}. A few groups have managed to pursue successful experimental programs in countries with comparatively long traditions in applied and basic research in the nuclear sciences; the chief examples being Argentina, Brazil, Chile, and Mexico, countries where research is fostered through collaborative efforts through annual national nuclear physics conferences. Two of these countries Brazil, site of the V LASNP, and Argentina, site of the VI LASNPA, have launched initiatives to construct large facilities allowing for their use by the wider international nuclear physics community: the Brazilian National Synchrotron Light Laboratory (LNLS) in Campinas (about 70 miles west of S\~{a}o Paulo) and the Tandar heavy ion accelerator in Buenos Aires, Argentina. Other countries in the region which have recently initiated activities aimed to improve their academic and scientific infrastructure in the nuclear sciences include Bolivia, Colombia, Peru and Venezuela.

\medskip \begin{center} \underline{\sf The Opportunity} \end{center}

There is ample room for collaborative overlap between the two hemispheres. Establishing links between the United States and Latin America will provide a means for recruiting high-caliber graduate-level students and post-doctoral fellows to pursue research at US institutions and laboratories such as JLab, RHIC, ORNL, RIA, and IAC. Such an academic relationship between North and South America will further strengthen the scientific endeavors of the nuclear physics communities of both continents. There is at present a dearth of graduate students pursuing advanced degrees in experimental and theoretical nuclear physics at US universities. This shortage is keenly felt at the national laboratories and facilities, where there is an abundance of Ph.D. theses topics and a paucity of graduate students. The goal is to build ties with faculty and students. While attracting students to US graduate programs, we also wish to build new groups and infrastructure in Latin America that would give the students an attractive career option in their home country after graduation.

%\newpage %\medskip \begin{center} \underline{\sf The Means and the Goals} \end{center}

We seek to grow these outreach efforts and our group will continue to write funding grants to the NSF Americas Program for sponsoring students to attend future interactions of the Latin American Symposium for Nuclear Physics and Applications. CoPI Cole was recently elected to the ten-member board International Organizing Committee of the VIII Latin American Symposium on Nuclear Physics and Applications to be held in Santiago, Chile, December 15-19, 2009. As in the past, the Committee's responsibilities include the scientific program, formation of an International Advisory Board, and some key aspects of the overall organization of the Symposium. Of this membership, three members are from Universities in the United States. With a colleague in Argentina, CoPI Cole further will write a grant to the International Atomic Energy Agency to help defray travel expenses for non-U.S.~students in Latin America, where typically funding from the NSF cannot be obtained.

\subsection{Graduate Student Training and Marketability}

\hspace{0.5in} The role graduate students play in the experiments which take place within our program provide them with marketable skill sets. Maria Novovic and Jena Kraft are clear examples of the impact members of this group have had training an underrepresented group in physics. Maria Novovic was trained in data acquisition, scintillator construction, and data analysis. She is currently a staff physicist at the University of Southern Alabama and is responsible for the undergraduate physics laboratories in addition to her undergraduate instructor role. The graduate training and experiences in PI Forest's lab were instrumental in securing her current position. Jena Kraft, who found a position in industry, reported that her design skills acquired while making a high pressure gas chamber for the GEM detector during her thesis were a key ingredient to her current position. The detector construction and instrumentation projects described in this proposal will continue to be effective in training graduate students for the market place. The Intermediate Energy Nuclear Physics Group at Idaho State University currently has three graduate students, listed in Table~\ref{table:Students}, working on JLab physics. Our expectation is that this number will increase with the addition of two faculty with JLab projects and the annual influx of more than 10 incoming graduate students per year.


Facilities

\hspace{0.5in}The Idaho State University Department of Physics Strategic Plan identifies the use of experimental nuclear physics techniques as its focus area to addressing problems in both fundamental and applied science. The major efforts of the department include fundamental nuclear and particle physics, nuclear reactor fuel cycle physics, nuclear non-proliferation and homeland security, accelerator applications, radiation effects in materials and devices, biology and health physics. Because of this focus, the department has been characterized as one of the largest nuclear physics graduate programs in the nation with an average of over 50 graduate students. One of the key ingredients to the department's success has been the completion of the Idaho Accelerator Center (IAC) on April 30, 1999. A substantial amount of lab space (4000 sq. ft.) within the department has become available due to a combination of the IAC and a remodeling of the physics building. A detector lab with the potential to construct proto-type drift chambers in a clean room environment is currently planned as part of the lab space renovation.

The Idaho Accelerator Center (IAC) is located less than a mile away from campus and will provide a machining facility for detector construction, an electronics shop for installation of instrumentation, and beam time for detector performance studies. The IAC houses ten operating accelerators as well as a machine and electronics shop with a permanent staff of 8 Ph.D.'s and 6 engineers. Among its many accelerator systems, the Center houses a Linac capable of delivering 20 ns to 2 $\mu$s electron pulses with an instantaneous current of 80 mA up to an energy of 25 MeV at pulse rates up to 1kHz. The IAC has donated beam time to the Q$_{weak}$ project for the purpose of testing detector performance. One of the goals of these tests will be to evaluate the Q$_{weak}$ detector at high rates. The IAC is well suited for these rate tests as the Q$_{weak}$ calibration rates will be much lower than the electron and photon rates the IAC is capable of generating. A full description of the facility is available at the web site (www.iac.isu.edu).

The Beowulf REsource for Monte-carlo Simulations (BREMS) is a 12 node, 64 bit cluster housed in the ISU physics department which can support the high performance computing needs of the physics research program. This facility is the result of an investment made by NSF award PHYS-987453. This infrastructure will be an effective means for performing GEANT4 simulations of the Q$_{weak}$ experiment as well as Garfield simulations of the Region II drift chamber design. Simulation speed is increased on BREMS by running the simulation in parallel on many CPUs. A version of GEANT4 known as ParGeant4~\cite{ParGeant4} has recently been distributed which will allow these simulations to be run in parallel.

The Broader Impact of the Idaho State University Nuclear Physics Research Program

The Americas

Our broader impacts activities are directed towards the Americas, cental and south. Over the past nine years, the two CoPIs have have been active in outreach towards Latin America. CoPIs Dale and Cole can both communicate in Spanish. Indeed, this past year CoPI Cole successfully completed Spanish 201 and 202 at ISU, as a Freshman with an undeclared major, and he is presently enrolled in an advanced Spanish composition course at the 300-level in the effort to attain fluency. Speaking Spanish is necessary for our broader impacts activities. South American physics students tend to read English rather well, but speaking good English is entirely another matter. To attract students, one needs to present the many research opportunities in medium nuclear physics the United States while dispelling subtle and not-so-suble misconceptions, which abound. And to communicate these matters, it is imperative to speak good Spanish.

We seek to promote dialogue between faculty members of North-American and Latin-American institutions by finding common interests in research which will allow for coordinating our programs in nuclear physics research. Through this effort, we expect to strengthen existing links and forge new ones within the broad scope of the international nuclear physics community. CoPI has been a PI four times and a CoPI twice on six separate Americas Program grants, which amounts in \$130k in funding.


\medskip \begin{center} \underline{\sf Funding History} \end{center}

\begin{itemize} \item The {\sf III Latin American Workshop on Nuclear and Heavy Ion Physics} (PI: Phil Cole) NSF-INT-9907453 for \$15,000

\item {\sf A Collaborative Effort between the U.S. and Colombia on the Physics with Linearly Polarized Photons}. (PI: Phil Cole) NSF-OISE-0101815 for \$32,590.

\item {\sf Americas Program: Student Sponsorship at the Fourth Latin American Symposium on Nuclear Physics, Mexico City, Mexico, September 24-28, 2001.} (PI: Phil Cole) NSF-OISE-0117545 for \$23,369


\item {\sf US-Brazil Student Sponsorship at the Fifth Latin American Symposium on Nuclear Physics; Santos, Brazil, September 1-5, 2003} (PI: Phil Cole, CoPI Jorge Lopez) NSF-OISE-0313656 for \$18,000

\item {\sf U.S.-Argentina Collaborative Workshop in Nuclear Physics and Its Applications} (PI: Chaden Djalali, CoPI: Phil Cole) NSF-OISE-0527110 for \$32,200.

\item {\sf US-Peru Workshop in Nuclear Physics and Its Applications, June 11-16, 2007, Cusco, Peru} (PI: Chaden Djalali, CoPI: Phil Cole) NSF-OISE-0652360 for \$32,200. See: VII Latin American Symposium on Nuclear Physics and Applications, AIP Conference Proceedings 947 (2007), Editors: Ricardo Alarcon, Philip L.~Cole, Chaden Djalali, and Fernando Umeres.

\end{itemize}

Recent outcomes of our links with the Latin American community include Mr. Tulio Rodrigues visit to Jefferson Lab in August 2004 to work with Dr.~Dan Dale on theoretical calculations for the PrimEx experiment. At the time CoPI Dale was at the University of Kentucky. Mr.~Rodrigues was supervised by Dr.~Arruda-Neto, head of the Nuclear Reactions and Structure Research Group at the Physics Institute of the University of S\~{a}o Paulo and received his PhD in 2006. Dr.~Rodrigues has visited ISU twice in the past two years to work on PrimEx-related physics. Another graduate student, Mr.~Vladimir Montealegre from the Universidad de los Andes in Bogot\'{a}, Colombia, entered the PhD program at the University of South Carolina. Our recruitment efforts are paying off. Our group now has two strong PhD students, Juli\'{a}n Salamaca and Danny Mart\'{\i}nez, from Colombia and upon processing the necessary paperwork, two more PhD students from Colombia will join us in January, 2009.


\medskip \begin{center} \underline{\sf The Need} \end{center}

Lack of modern equipment is one of the main obstacles to applied research in the less-developed Latin American countries. There is, however, considerable variation in the size and influence of the physics community by individual countries ~\cite{MoranLopez}. A few groups have managed to pursue successful experimental programs in countries with comparatively long tradition in applied and basic research in the nuclear sciences; the chief examples being Argentina, Brazil, Chile, and Mexico, countries, where research is fostered through collaborative efforts through annual national nuclear physics conferences. Two of these countries Brazil, site of the V LASNP, and Argentina, site of the VI LASNPA, have launched initiatives to construct large facilities allowing for its use by the wider international nuclear physics community: the Brazilian National Synchrotron Light Laboratory (LNLS) in Campinas (about 70 miles west of S\~{a}o Paulo) and the Tandar heavy ion accelerator in Buenos Aires, Argentina. Other countries in the region which have recently initiated activities aimed to improve their academic and scientific infrastructure in the nuclear sciences include Bolivia, Colombia, Peru and Venezuela.

\medskip \begin{center} \underline{\sf The Opportunity} \end{center}

There is ample room for collaborative overlap between the two hemispheres. Establishing links between the United States and Latin America will provide a means for recruiting high-caliber graduate-level students and post-doctoral fellows to pursue research at US institutions and laboratories such as JLab, RHIC, ORNL, RIA, and IAC. Such an academic relationship between North and South America will further strengthen the scientific endeavors of the nuclear physics communities of both continents. There is at present a dearth of graduate students pursuing advanced degrees in experimental and theoretical nuclear physics at US universities. This shortage is keenly felt at the national laboratories and facilities, where there are an abundance of PhD theses topics and a paucity of graduate students. The goal is to build ties with faculty and students. While attracting students to US graduate programs, we also wish to build new groups and infrastructure in Latin America that would give the students an attractive career option in their home country after graduation.

%\newpage \medskip \begin{center} \underline{\sf The Means and the Goals} \end{center}

We seek to grow these outreach efforts and our group will continue to write funding grants to the NSF Americas Program for sponsoring students to attend future interations of the Latin American Symposium for Nuclear Physics and Applications. CoPI Cole was recently elected to the ten-member board International Organizing Committee of the VIII Latin American Symposium on Nuclear Physics and Applications to be held in Santiago, Chile, December 15-19, 2009. As in the past, the Committee's responsibilities include the scientific program, formation of an International Advisory Board, and some key aspects of the overall organization of the Symposium. Of this membership, four members are from Universities in the United States. CoPI Cole further will write a grant to the International Atomic Energy Agency to help defray travel expenses for non-U.S.~students in Latin America, where typically funding from the NSF cannot apply.

Graduate Student Training and Marketability

hspace{0.5in} The role graduate students play in the experiments which take place within our program provide them with marketable skill set. Maria Novovic and Jena Kraft are clear example of the impact member of this group has had train ing an underrepresented goup in physics. Maria Novovic was trained in data acquisition, scintillator construction, and data analysis. She is currently a staff physicist at the University of Southern Alabama and is responsible for the undergraduate physics laboratories in addition to her undergraduate instructor role. The graduate training and experiences in Dr. Forest's lab were instrumental in securing her current position. Jena Kraft, who found a position in industry, reported that her design skills acquired while making a high pressure gas chamber for the GEM detector during her thesis were a key ingredient to her current position. The detector construction and instrumentation projects described in this proposal will continue to be effective in training graduate students for the market place. The Intermediate Energy Nuclear Physics Group at Idaho State University currently has three graduate students, listed in table~\ref{table:currentstudents}, working on JLAB physics. Our expectation is that this number will increase with this years addition of two faculty with JLAB projects and the annual influx of more than 10 incoming graduate students per year.

Budget Justification

The three senior personnel on this project, Dr. Phil Cole, Dr. Dan Dale, and Dr. Tony Forest, each have established physics programs at Jefferson Lab and will continue to pursue those endeavors using the support itemized in the budget. Almost 40% of the budget in this proposal is devoted to supporting several graduate students currently pursuing their Ph. D. degrees within the JLab research program. Two undergraduate students will also continue to be supported by this grant. Undergraduates supported in past years have made substantial contributions to the program while gaining research experience. The support from this grant will be used to extend those experiences to include accelerator operations. We plan to use undergraduates as operators of the accelerators we will be using to provide ionizing radiation for testing the detectors we build.

Our travel budget is based on the number of shifts we expect to take at JLAB as well as several collaboration meetings we will need to attend. The ISU group was assigned 32 CLAS shifts in 2008 which requires at most 8 trips to JLab when the shifts are taken in blocks of 4. Our past experiences indicate that the costs of an individual trip to JLAB from Idaho range between $1,200 and $2,000 per trip. We estimate that we will spend approximately $16,000 per trip in order to absorb the market fluctuations as well as the probably increases in travel costs. Each PI expects to attend at least 3 collaboration meetings per year. The PI's have substantial roles in the Qweak, PRIMEX, and CLAS collaborations. We estimate a cost of $18,000 for this travel. We also expect to present the results of our work at conferences each year and request $4,000 to defray those costs.

A shipping budget for $100 is requested to support the exchange of materials between JLab and ISU as we move towards construction of the RI tracking system for CLAS12. Our Laboratory for Detector Science expends on average $3000 in consumables each year. We expect to upgrade or replace an average of 1 computer each year which is used for data acquisition or analysis at a cost of $2000. We will also add to our data acquisition system by purchasing a NIM/VME modules at a cost of $5000. During the first we plan to purchase two gate generators for digital signal generation and a VME module for producing LVDS signals. The LVDS signal module will be used to test the front end electronics of the Qweak Region 1 tracking system. In year two we plan on purchasing F1 TDC's for the purpose of measuring the performance of Drift Chambers developed as part of the CLAS 12 GeV upgrade. We plan on purchasing several more channels of leading edge discriminators and post amplifiers in the final year to increase the number of detector channels we are capable of measuring with out current CODA based DAQ system.

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