Difference between revisions of "2008 NSF Proposal"

From New IAC Wiki
Jump to navigation Jump to search
 
(54 intermediate revisions by one other user not shown)
Line 1: Line 1:
= NSF Proposal Guide=
+
[[ForestNSFInterimReport_8-31-10]]
  
d. Project Description (including Results from Prior NSF Support)
+
[[ForestNSFInterimReport_8-31-11]]
 
 
(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 =
 
 
 
The PI's in this proposal, while being a newly formed group, have an established program in experimental nuclear physics based at Jefferson Lab which seeks to perform measurements that contribute to an understanding of hadronic interactions.  The impact the measurements made within this program to our present state of knowledge in this field is described in the section ~\ref{sect:IntellectualMerits}. 
 
 
 
 
 
The group plans to continue to capitalize on it's recruitment of graduate students from the Americas, established by Dr. Cole using previous NSF awards, by training the students from this underrepresented geographic group in our proposed activities of detector development described by our work plan in section ~\ref{sect:WorkPlan}.
 
 
 
==Intellectual Merit==
 
==Broader Impacts==
 
 
 
=Intellectual Merit of the Proposed Activity=
 
== 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}===
 
 
 
The <math>Q_{weak}</math> experiment (E05-008) will use parity violating (PV)
 
electron-proton scattering
 
at very low momentum transfers <math>(Q^2  \sim  0.03 GeV^2)</math> to measure
 
the weak mixing
 
angle <math>\sin^2(\theta_W)</math>.
 
The dominant contribution to the PV
 
asymmetry measured by <math>Q_{weak}</math> is given by the weak charge of
 
the proton, $Q_W^p = 1-4\sin ^2 \theta _W$,
 
with small corrections at 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. 
 
The experiment is scheduled for installation in the beginning of 2010.
 
The role of the principal investigator in this program is
 
described in section~\ref{section:QweakDetector}.  A brief
 
description of the physics behind the Qweak experiment is 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},
 
and 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.
 
 
 
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
 
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
 
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
 
has determined $\sin ^2 \theta _W$ from PV $\vec e e$ (Moller) scattering (which
 
resides in the pure leptonic sector) 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, and 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.
 
 
 
 
 
 
 
[[Image:Qweak_s2w_Precision.jpg | 200 px]][[Image:Qweak_s2w_Precision.eps]]
 
 
 
\begin{figure}[htbp]
 
%\vspace{-1in}
 
\centerline{
 
\scalebox{0.5} [0.5]{\includegraphics{Graphs/s2w_2004_4_new_2.eps}}}
 
\caption{The dependence of $\sin^2 \theta_W$ as a function of
 
$Q^2$ cast in the MS bar scheme by reference~\cite{Erler}.  The
 
solid line represents the Standard Model prediction.
 
The results from three 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 <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
 
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 Reference\cite{Zhu012} estimate that this enhancement may
 
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
 
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.
 
 
 
 
 
[[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===
 
 
 
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
 
 
 
 
 
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
 
PhD 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 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
 
proceeds primarily through pomeron exchange rather by $\pi$ or $\eta$ meson
 
exchange, which are respectively termed natural and unnatural parity exchange.
 
In the baryon resonance energy regime ($\sim E_{\vec{\gamma}}=2.0$ GeV) and
 
at low four-momentum squared transfer, $t$,
 
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===
 
 
 
\section{The {\em PrimEx} Experiment}
 
 
 
One of the Co-PI's for this proposal is a spokesperson the 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. If we
 
limit ourselves to 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.
 
 
 
 
 
  In the limit of 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}
 
 
 
where the reduced amplitude
 
 
 
\begin{equation}
 
A_{\gamma \gamma} =\frac{\alpha_{em}}{\pi F_{\pi}} = 2.513 \cdot
 
10^{-2} GeV^{-1}
 
\end{equation}
 
 
 
 
 
The crucial aspect of this expression is that it has no free parameters
 
that need to be determined phenomenologically. In addition, 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 such a fundamental quantity, and in
 
particular for 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 have been 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.
 
The measurement of the decay width of the $\pi^0$ with a precision comparable to these calculations 
 
will provide an important test of
 
the fundamental QCD predictions.
 
 
 
[[Image:pio_width_new_theory_prel_result.eps]]
 
 
 
\begin{figure}
 
\centering
 
\psfig{figure=pio_width_new_theory_prel_result.eps,height=6.0in,width=6.0in}
 
\caption{$\pi^{o} \rightarrow \gamma \gamma$ decay width in eV. The
 
dashed horizontal line is the leading order prediction
 
of the axial anomaly (equation 3)\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.}
 
\label{fig:theory}
 
\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 \$960k
 
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. The preliminary results  demonstrate
 
that we are able to control the systematic errors with the designed precision. 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,
 
(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==
 
 
 
=== 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.
 
 
 
 
 
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 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. 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 collimator divides the φ acceptance into 8 regions, octants, and reduces the azimuthal acceptance by almost 30 percent. The right hand figure below shows the elastic scattering profile overlayed on top of one of the octants. The Region 1 tracking system will measure the electron scattering angle at only 2 of the octants at a time and will rotate in φ to perform measurements in the remaining octants.
 
 
 
The high radiation flux and the small detector footprint are two of the biggest challenges facing the Region 1 tracking system. 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. The ionization chamber itself is constructed from Ertalyte, a machinable plastic material which can withstand the high radiation environment. The material's strength allows the chamber to have thin walls which prevent the chamber from extending into adjacent octants. The three major components to the Qweak Region 1 detector are the GEM preamplifiers, the charge collector, and the ionization chamber are describe below.
 
 
 
 
 
The figure below shows the custom designed GEM preamplifier for the Qweak Region 1 tracking system.  The preamplifier is a 50 micron thick kapton foil clad on both sides with 5 microns of copper.  Holes are etched into the foil such that a high voltage (HV) applied across the top and bottom copper plates will create an electric field strong enough to cause charge to pass through the hole and multiply much like the avalanche region of a drift chamber.    Engineers from the Idaho Accelerator Center (IAC) designed the shape of the foils and the location of 6 tabs used for HV connections, as shown in the left hand figure below.  This generic design allows one to use the part for any GEM amplification stage simply by cutting off the unused HV tabs.  The actual preamp is shown on the right hand side of the figure below.  Although this is a simple part, it is a clear example of how the infrastructure at the IAC can be leveraged in support of our physics mission.
 
 
 
[[Image:Qweak_GEM_preamp.jpg | 300 px]]
 
[[Image:Qweak_GEM_preamp_TecEtch.jpg | 300 px]]
 
 
 
 
 
The charge collector for Qweak's region 1 tracking system is shown below. The copper charge collector strips are aligned in terms of the electron scattering angle θ. Each of the red strips shown in the right hand figure below is 400 microns wide and will measure the elastic electron scattering angle to within 0.1 mrad. The blue lines shown in the left hand figure are representative of the φ scattering angle. A large number of graduate student hours were needed to place each strip into the correct position using PC board design software. Software compatibility issues with the vendor were also a major time sink of several months before the part could be accurately manufactured according to our specifications. This single part represents the bulk of a graduate students effort for the past 6 months and is one example of a practical component to a students educational experience.  Two charge collectors have already been received but had two small errors which have been correct.  Although the vendor for this part has had production difficulties resulting in delays of several months, the part and is expected to arrive by the end of October, 2008. 
 
 
 
 
 
[[Image:BOTTOM_copper.jpg | 200px]][[Image:TOP_copper.jpg | 200px]]
 
[[Image:CERN_Qweak_Charge_Collector_2.jpg | 200px]]
 
<br>
 
 
 
 
 
The ionization chamber for the Qweak Region 1 tracking system needs to have a small profile in order to be placed less than a quarter meter after the target.  A collimator in front of this detector divides the electron scattering anglular range into octants which reduce the angular acceptance range by about 30 percent.  The goal was to construct a chamber which did not interfere with the other octants and be transportable between octants.  The figure below shows the top half of the ionization chamber which has been built.  As seen in the figure, the electron profile is enclosed by the detector acceptance and the ionization chamber frame is in the shadow of the collimator.  The HV distribution board has been designed by physics undergraduate student Jordan Keough and is ready to be sent out for production.  Chamber construction will be completed when the charge collector arrives from the vendor and is installed.  We expect to test the chamber in August, 2008.
 
 
 
 
 
====pair spect====
 
 
 
====Brem facility====
 
 
 
=== 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.
 
 
 
==== Polarized Structure Functions====
 
<math>\frac{\Delta d}{d}</math>
 
 
 
\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
 
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{center}{
 
\scalebox{0.4} [0.5]{\includegraphics{Graphs/delq_new1.eps}}
 
\scalebox{0.4} [0.5]{\includegraphics{Graphs/deltad_CLAS12.eps}}
 
}
 
\caption{The polarized to unpolarized up and down quark
 
distribution ratio. The left figure shows the results
 
from recent JLab experiments on the virtual photon asymmetry $A_1$ for
 
the proton, Deuteron~\cite{EG2DeltaD} and neutron
 
($^3$He)~\cite{HallADeltaD}.  The right figure represents the
 
proposed measurements.  The expected data have been draw along
 
the pQCD and CQM prediction. }
 
\label{delqJLab}
 
\end{center}
 
\end{figure}
 
 
 
 
 
The comprehensive data set to be
 
collected by experiment PR12-06-109 will contribute
 
substantially to our knowledge of polarized parton distribution
 
functions for all quark flavors and even the polarized
 
gluon distribution $\Delta g$. Through Next-to-Leading Order (NLO) analysis
 
of the world data on inclusive DIS (using the DGLAP
 
evolution equations), one can constrain these
 
distribution functions and their integrals. Existing CLAS data
 
from 6 GeV have already made an impact on these fits. The
 
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====
 
==== 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 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====
 
 
 
{| border="1"  |cellpadding="20" cellspacing="0
 
|-
 
|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
 
|-
 
|Saitiniyazi Shadike || M.S.  || 2009
 
|-
 
|Jordan Keonough || BS  || 2011
 
|-
 
|Nathan Lebaron|| BS  || 2012
 
|}
 
 
 
==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.
 
 
 
=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.
 
 
 
[http://www.iac.isu.edu/mediawiki/index.php/NSF Go Back]
 

Latest revision as of 22:02, 23 August 2011