9/5/08

SIDIS Analysis

a.) Cross-Section comparison

i.) Calculate absolute cross section for [math]\cos(\theta_{pi})[/math] = 0.5, 1 < Q^2 < 4 GeV^2 , W = 1.45 +/- 0.2 GeV

ii.) Plot [math]\phi_{diff}^{CM}[/math]-vs-[math]cos{\theta}_{\pi}^{LAB}[/math] when [math]cos{\theta}_{e}^{CM}[/math] = -0.3 also plot [math]\phi_{diff}^{CM}[/math]-vs- [math]cos{\theta}_{e}^{LAB}[/math]

As one can see from histograms of the pion_theta_angle_vs_phi_angle_in_CM_Frame and the electron_theta_angle_vs_phi_angle_in_CM_Frame, the pion and electron acceptance in the region of [math]\phi_{diff}^{CM}=180[/math] is nearly zero(significantly low).

electron sector	pion_theta_angle_vs_phi_angle_in_CM_Frame_after_cuts(EC_inner>0.06, EC_tot/p>0.2, nphe>2.5, [math]0.9\lt M_x\lt 1.1[/math], [math]1.1\lt W\lt 1.5[/math] )	electron_theta_angle_vs_phi_angle_in_CM_Frame_after_cuts(EC_inner>0.06, EC_tot/p>0.2, nphe>2.5, [math]0.9\lt M_x\lt 1.1[/math], [math]1.1\lt W\lt 1.5[/math] )
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2
3
4
5
6

[math]Q^2[/math]_vs_[math]\phi_{diff}^{CM}[/math] plot shows that the [math]Q^2[/math] cut should not make much difference on [math]\phi_{diff}^{CM}[/math] plot. The cut around should reduce the number of pions around 0 and 360 of phi angle.

9/19/08

SIDIS Analysis

a.) Cross-Section comparison

i.) Calculate absolute cross section for [math]\cos(\theta_{pi})[/math] = 0.5, 1 < Q^2 < 4 GeV^2 , W = 1.45 +/- 0.2 GeV

[math]\frac{d \sigma}{d \Omega^*_{\pi}} = \frac{1.061 \times 10^{-3} [\mu barn]}{0.88} = 0.0012 \ne 2.4[/math]?

Documentation

The five-fold differential cross section for single pion production is equal to the following:

The Jacobian term can be given as:

where [math]\Gamma_{v}[/math] is the virtual photon flux and can be written as

The reason of having low cross section might be binning

In paper they use the following number of bins:

Variable	Num. Bin	Range	Bin Size
W	27	1.15 - 1.7 GeV	20 MeV
[math]Q^2[/math]	7	1.1 - 5.0 [math]GeV^2[/math]	variable
[math]cos {\theta_{\pi}}^*[/math]	10	-1.0 - 1.0	0.2
[math]{\phi_{\pi}}^*[/math]	24	-180. - 180	15

Number of bins in my case were 360.

Number of bins equal is ~24

When i applied [math]1.6\lt Q^2\lt 1.84[/math] cut, the number of entries were reduced to 152.

In paper they use liquid-hydrogen unpolarized target(we have NH3 and ND3 polarized). The polarized electron beam current is 8 nA(in our case it is about 6 nA). and luminosity is different too. It also depends on statistics.

ii.) What is smallest angular coverage of EC (8 degrees?) Determine phi region where there is no acceptance ( where should we stop plotting data)?

iii.) Asymmetry Calculation

a.) Beam Asymmetry Plot

In order to plot Beam Asymmetry we need to plot for the first time the histogram of the invariant_mass_vs_cross_section. Then determine the structure function fitting the cross section and calculating the beam asymmetry function which is given as :

for given cos(theta) of the pion in cm, Q^2 and W invariant mass.

Choose kinematics ( a single theta and phi point )to max our stats and comparison to paper Histogram the following

Number of e-pi coincidence events, number of FC counts
Number of e-pi coincidence events/FC counts
Number of e-pi coincidence events/FC count/Pt

for groups of runs with h_e,P_t = ++, +-, -+, --

table with 4 columns of h_e, P_t and 3 rows of the above histograms

9/26/08

SIDIS Analysis

1.) make semi-inclusive spectrum:

a.) h>0 Pt>0 b.) h > 0 pt<0 c.)h<0 pt>0 d.)h<0 pt<0

2.) ad up opposite target polarization histograms

3.) subtract h> 0 and h<0

helflag = 1 =>

helflag = 2 =>

helflag = 3 =>

helflag = 4 =>

Phi_angle_CM vs Asymmetry

Compared data(there is no table for asymmetry values like cross section):

11/21/08

0.) insert run summarry table, Pb, Pt, PB*Pt, Btorus

1.) make semi-inclusive spectrum:

a.) h>0 Pt>0

b.) h > 0 pt<0

c.)h<0 pt>0

d.)h<0 pt<0

2.) helicity difference plots for Pt>0 and Pt<0

3.) Asym plots for Pt>0 and Pt< 0

4.) unpolarized target asymmetry

Rebin asymmetry hisograms and combine the two into a total asymmetry histogram

Run Summary Table

The table below should have run ranges with 
[math]P_b*P_t \pm \Delta (P_b *P_t)[/math] according 
to the elastic asymmetry measurements stored at
http://www.jlab.org/Hall-B/secure/eg1/EG2000/eg1b_analysis_progress.htm.

http://www.jlab.org/Hall-B/secure/eg1/EG2000/josh/pbpt/

Start Run Number	Beam Polarization(Pb)	Target Polarization(Pt)	Pb*Pt	Beam Torus	Beam Energy (MeV)
26998	0	-0.69		-2252	5736
26996	-0.71	-0.69		-2248	5736
26995	-0.71	-0.69		-2252	5736
26994	-0.71	-0.73		-2250	5736
26993	-0.71	-0.72		-2248	5736
26992	-0.71	-0.73		-2252	5736
26991	-0.71	-0.75		-2250	5736
26990	-0.71	-0.76		-2248	5736
26989	0.71	-0.67		2248	5736
26988	0.71	-0.68		2250	5736
26987	0.71	-0.67		2248	5736
26986	0.71	-0.68		2250	5736
26985	0.71	-0.68		2252	5736
26984	0.71	-0.68		2250	5736
26983	0.71	-0.68		2248	5736
26981	0.71	-0.68		2250	5736
26980	0.71	-0.7		2253	5736
26979	0.71	-0.71		2252	5736
26966	0.71	0.74		2253	5736
26965	0.71	0.74		2248	5736
26964	0.71	0.74		2252	5736
26963	0.71	0.74		2250	5736
26962	0.71	0.74		2252	5736
26961	0.71	0.75		2250	5736
26960	0.71	0.76		2250	5736
26959	0.71	0.69		2252	5736
26958	0.71	0.69		2250	5736
26957	0.71	0.69		2252	5736
26956	0.71	0.69		2250	5736
26955	0.71	0.69		2253	5736
26954	0.71	0.69		2252	5736
26953	0.71	0.69		2248	5736
26952	0.71	0.7		2250	5736
26951	0.71	0.7		2250	5736
26948	0.71	0.7		2250	5736
26947	0.71	0.7		2252	5736
26946	0.71	0.7		2252	5736
26945	0.71	0.7		2252	5736
26943	0.7	0.7		2252	5736
26942	0.7	0.7		2248	5736
26941	0.7	0.7		2250	5736
26940	0.7	0.7		2250	5736
26939	0.7	0.7		2252	5736
26938	0.7	0.7		2253	5736
26937	0.7	0.7		2257	5736
26934	0.7	0.7		2250	5736
26933	0.7	0.71		2253	5736
26932	0.7	0.71		2252	5736
26931	0.7	0.71		2252	5736
26930	0.7	0.71		2250	5736
26929	0.7	0.71		2250	5736
26928	0.7	0.72		2250	5736
26927	0.7	0.72		2252	5736
26926	0.7	0.73		2250	5736
26925	0.7	0.73		2253	5736
27074	0.71	-0.81		2252	5736
27075	0.71	-0.77		2250	5736
27076	0.71	-0.74		2248	5736
27077	0.71	-0.74		2253	5736
27078	071	-0.75		2252	5736
27079	0.71	-0.72		2244	5736
27100	0.71	0.76		2250	5736
27101	0.71	0.76		2248	5736
27102	0.71	0.73		2252	5736
27105	0.61	0.73		2250	5736
27106	0.61	0.73		2252	5736
27107	0.61	-0.71		2250	5736
27108	0.61	-0.7		2248	5736
27109	0.61	-0.7		2255	5736
27111	0.61	-0.71		2252	5736
27112	0.61	-0.69		2252	5736
27114	0.61	0		2253	5736
27116	-0.58	0.2		2252	5736
27124	-0.7	0.24		2253	5736
27125	-0.7	0.25		2248	5736
27126	-0.7	0.26		2250	5736
27127	-0.7	0.26		2252	5736
27128	-0.7	0.26		2250	5736
27129	-0.7	0.26		2252	5736
27131	-0.7	0.26		2250	5736
27132	-0.7	0.26		2252	5736
27133	-0.7	0.26		2250	5736
27134	-0.7	0.26		2250	5736
27135	-0.7	0.26		2246	5736
27136	-0.7	0.26		2250	5736
27137	-0.7	0.25		2252	5736
27138	-0.7	0.25		2252	5736
27139	-0.7	0.25		2252	5736
27141	-0.7	0.25		2250	5736
27142	-0.7	0.25		2252	5736
27143	-0.7	0.25		2248	5736
27145	-0.7	0.24		2252	5736
27146	-0.7	0.24		2250	5736
27148	-0.7	0.24		2252	5736
27149	-0.7	-0.09		2253	5736
27150	-0.7	-0.12		2252	5736
27152	-0.64	-0.18		2252	5736
27153	-0.64	-0.19		2253	5736
27154	-0.64	-0.19		2248	5736
27155	-0.64	-0.19		2250	5736
27156	-0.64	-0.19		2248	5736
27157	-0.64	-0.19		2252	5736
27160	-0.64	-0.18		2253	5736
27161	-0.64	-0.18		2250	5736
27162	-0.64	-0.19		2252	5736
27163	-0.64	-0.19		2250	5736
27165	-0.64	-0.19		2248	5736
27166	-0.64	0.18		2250	5736
27167	-0.64	0.22		2250	5736
27168	-0.64	0.23		2253	5736
27169	-0.64	0.23		2250	5736
27170	-0.64	0.23		2250	5736
27171	-0.64	0.23		2252	5736
27172	-0.64	-0.35		2250	5736
27175	-0.7	-0.78		2250	5736
27176	-0.7	-0.72		2250	5736
27177	-0.7	-0.7		2252	5736
27178	-0.7	-0.69		2250	5736
27179	-0.7	-0.67		2252	5736
27180	-0.7	-0.67		2250	5736
27181	-0.7	-0.66		2252	5736
27182	-0.7	-0.72		2252	5736
27183	-0.7	-0.68		2252	5736
27184	-0.7	-0.63		2250	5736
27186	-0.7	0.72		2250	5736
27187	-0.7	0.71		2250	5736
27188	-0.7	0.71		2248	5736
27189	-0.7	0.7		2252	5736
27190	-0.7	0.69		2252	5736
27191	-0.7	0.69		2248	5736
27192	-0.7	0.68		2248	5736
27193	-0.7	0.69		2253	5736
27194	-0.7	0.7		2252	5736
27195	-0.7	0.69		2250	5736
27113	0.61	0.68		2250	5736