Study of elastic asymmetry

Go to : Corrected counts asymmetry (updated May 5, 2005)

Go to : Dilution factor (updated May 5, 2005)

Go to : Physics asymmetry   (updated June 24, 2005)

Go to : Elastic Cross section (updated Dec 20, 2005)

Go to : Nitrogen asymmetry contribution    (updated June 23, 2005)

Go to : Comparison of C+He to N+He background    (updated Apr. 5, 2005)

Go to : Asymmetries in four electron scattering angle regions    (updated May 6, 2005)

Go to :Asymmetries in two electron scattering angle regions   (updated May 23, 2005)

Go to :Systematic Studies (updated July 8, 2005)

Corrected counts asymmetry:
Use the kumac to determine the corrected counts asymmetry as a function of W for a weighted average of all runs. Used cut of abs(hsdelta)<8 and 0.8<(hsshtrk/hsp)<1.4 . The count asymmetries are corrected for the target and beam polarization for the run. In addition, the top target runs are corrected by a factor of 1/1.019 and the bottom by 1/1.018 . For parallel bottom target multiplied the asymmetry by 1.18 . The sign of the asymmetry is reversed in the kumac. Plots of the count asymmetry for parallel and perpendicular target runs. ( Had problems with run 43801 so it was not used)
Use the kumac to determine the corrected counts asymmetry as a function of W for a weighted average of all runs. Used cut of abs(hsdelta)<12 and 0.8<(hsshtrk/hsp)<1.4 . The count asymmetries are corrected for the target and beam polarization for the run. In addition, the top target runs are corrected by a factor of 1/1.019 and the bottom by 1/1.018 . For parallel bottom target multiplied the asymmetry by 1.18 . The sign of the asymmetry is reversed in the kumac. Plots of the count asymmetry for parallel and perpendicular target runs. ( Had problems with run 43801 so it was not used)
Dilution factor:
Use the kumac to fit the background shape (which is a gaussian + a second order polynomial) to the C+He run. Used cut of abs(hsdelta)<8 and 0.8<(hsshtrk/hsp)<1.4 . For parallel target field use run 43775. Plot of the fit to the data. For perpendicular target field use run 43407. Plot of the fit to the data. Using this shape for the background, the dilution factor is determined using the kumac which sums all the runs and normalizes the background shape in the region 0.7 < W < 0.85 GeV. Plots of the dilution factor for parallel and perpendicular target field.
Use the kumac to extract the data from combined C+He runs. For parallel target field use runs 43775,43776 and 43799.Used cut of abs(hsdelta)<8 and 0.8<(hsshtrk/hsp)<1.4 . Plot of the data. For perpendicular target field use runs 43227,43230,43285,43324, 43395 and 43396. Plot of the data. Using this shape for the background, the dilution factor is determined using the kumac which sums all the runs and normalizes the background shape in the region 0.7 < W < 0.85 GeV. Plots of the dilution factor for parallel and perpendicular target field.
Use the kumac to extract the data from combined C+He runs. For parallel target field use runs 43775,43776 and 43799.Used cut of abs(hsdelta)<8 and 0.8<(hsshtrk/hsp)<1.4 . Plot of the data. For perpendicular target field use runs 43227,43230,43285,43324, 43395 and 43396. Plot of the data. Using this shape for the background, the dilution factor is determined using the kumac which sums all the runs and normalizes the background shape in the region 0.7 < W < 0.80 GeV. Plots of the dilution factor for parallel and perpendicular target field.
Use the kumac to extract the data from combined C+He runs. Used cut of abs(hsdelta)<12 and 0.8<(hsshtrk/hsp)<1.4 . For parallel target field use runs 43775,43776 and 43799. Plot of the data. For perpendicular target field use runs 43227,43230,43285,43324, 43395 and 43396. Plot of the data. Using this shape for the background, the dilution factor is determined using the kumac which sums all the runs and normalizes the background shape in the region 0.7 < W < 0.85 GeV. Plots of the dilution factor for parallel and perpendicular target field.
Did same as above but used -9<hsdelta<10 cut. Made 15 MeV W bins. Plots of the dilution factor for parallel and perpendicular target field. Data files for top parallel , bottom parallel and top perp , bottom perp .
Physics asymmetry:
Use the kumac to combine the dilution factor and the corrected counts asymmetry into the physics asymmetry.
. Plots of the TE calibration for parallel and perp proton so that the top parallel had three good TE measurements while the bottom only had one good TE. A report by Oscar looked in detail at the TE for the parallel field proton target. The ratio of top to bottom TE's is 1.18 ( see mail). Use this factor to multiply the parallel bottom counts asymmetry.
( Previously, found that for parallel field the ratio of top/bottom asymmetry = 1.09 +- .028 . Averaging physics asymmetry for W > 1.34, one gets top/bottom asymmetry = 1.12 +- .036 )

For parallel target field expect the asymmetry = 0.2149 for theta_e = 12.97 (Q2 = 1.460) with phi_e = 182.46 degrees. The ratio of expected asym to measured top (bottom target) asymmetry is 1.045 +- 0.017 ( 0.965 +- 0.019).

Dilution factor method

Physics
Asymmetry plots

Asymmetry Top target

Asymmetry bottom target

Fit c+he data (one run) with
g+p2 scale to NH3 data
in region 0.7 < W< 0.85
Cuts abs(hsdelta)<8
and 0.8<(hsshtrk/hsp)<1.4

0.2074 +- 0.0033

0.2260 +- 0.0048

Extract C+he data ( multiple runs)
scale to NH3 data
in region 0.7 < W< 0.85
Cuts abs(hsdelta)<8
and 0.8<(hsshtrk/hsp)<1.4

0.2125 +- 0.0033

0.2315 +- 0.0049

Extract C+he data ( multiple runs)
scale to NH3 data
in region 0.7 < W< 0.80
Cuts abs(hsdelta)<8
and 0.8<(hsshtrk/hsp)<1.4

parallel

0.2100 +- 0.0033

0.2282 +- 0.0049

Extract C+he data
( multiple runs) scale to NH3
data in region 0.7 < W< 0.85
Cuts abs(hsdelta)<12
and 0.8<(hsshtrk/hsp)<1.4

parallel

No 15N corr	0.208 +- 0.0032
with 15N corr A(N) = -0.072 A(N)= -A(p)/3	0.208 +- 0.0032
with 15N corr A(N) = -0.308+-0.223 A(N) from data	0.206 +- 0.0032

No 15N corr	0.2262 +- 0.0046
with 15N corr	0.2257 +- 0.0045
with 15N corr	0.2238 +- 0.0045

Extract C+he data
( multiple runs) scale to NH3
data in region 0.6 < W< 0.85
Cuts abs(hsdelta)<12
and 0.8<(hsshtrk/hsp)<1.4
abs(hsxptar)<.12
abs(hsyptar)<.04

No 15N corr	0.2082 +- 0.0032
with 15N corr A(N) = -0.072 A(N)= -A(p)/3	0.2071 +- 0.0032
with 15N corr A(N) = -0.308+-0.223 A(N) from data	0.2052+- 0.0033

No 15N corr	0.2260 +- 0.0045
with 15N corr	0.2246+- 0.0045
with 15N corr	0.2227+- 0.0045

For perpendicular target field, expect the asymmetry = -0.103 for muGe/Gm = 0.837 at Q2 = 1.464 with phi_e = 169 degrees.

Dilution factor method

Physics
Asym
plots

Asymmetry Top target

Asymmetry bottom target

Fit c+he data (one run) with
g+p2 scale to NH3 data
in region 0.7 < W< 0.85
Cuts abs(hsdelta)<8
and 0.8<(hsshtrk/hsp)<1.4

perp

-0.1016 +- 0.0042

-0.1028 +- 0.0045

Extract C+he data ( multiple runs)
scale to NH3 data
in region 0.7 < W< 0.85
Cuts abs(hsdelta)<8
and 0.8<(hsshtrk/hsp)<1.4

perp

-0.1002 +- 0.0043

-0.0992 +- 0.0042

Extract C+he data ( multiple runs)
scale to NH3 data
in region 0.7 < W< 0.80
Cuts abs(hsdelta)<8
and 0.8<(hsshtrk/hsp)<1.4

perp

-0.0981 +- 0.0041

-0.0991 +- 0.0043

Extract C+he data
( multiple runs) scale to NH3
data in region 0.7 < W< 0.85
Cuts abs(hsdelta)<12
and 0.8<(hsshtrk/hsp)<1.4

perp

No 15N corr	-0.0992 +- 0.0041
with 15N corr A(N)= 0.034 A(N)= -A(p)/3	-0.0988+-0.0041
with 15N corr A(N)= -0.574+-0.245 A(N) from data	-0.1045 +- 0.0041

No 15N corr	-0.1003 +- 0.0043
with 15N corr	-0.1000 +- 0.0043
with 15N corr	-0.1053 +- 0.0043

Extract C+he data
( multiple runs) scale to NH3
data in region 0.6 < W< 0.85
Cuts abs(hsdelta)<12
and 0.8<(hsshtrk/hsp)<1.4
abs(hsxptar)<.12
abs(hsyptar)<.04

No 15N corr	-0.0992 +- 0.0041
with 15N corr A(N)= 0.034 A(N)= -A(p)/3	-0.0989 +-0.0041
with 15N corr A(N)= -0.574+-0.245 A(N) from data	-0.1043 +- 0.0042

No 15N corr	-0.1004 +- 0.0043
with 15N corr	-0.1000 +- 0.0043
with 15N corr	-0.1052 +- 0.0044

Comparison of pass2a and pass3: (update March 2005)
Plots of the dilution factor, corrected count asymmetry and physics asymmetry comparing pass2a to pass3 for parallel target field and top target cell.
Elastic cross section: (update Dec. 20, 2005)

Plots comparing the data to MC ( after fixing bug in MC which only effected elastic data). In Column 1, the combination of target field and target cup is listed with the packing fraction used. In column 2, the ratio of data for C+He to data NH3 fitted in the region of 0.6 < W < 0.85 . The plot shows Nh3 data with the C+He data ( in blue) normalized to the NH3 data. The elastic peak after subtracting the C+He data is shown in the bottom histogram in the figure. In column 3 is the ratio C+He to N+He yields in the MC. The agreement with the data ratio indicates that possible contamination from frozen 14N or ND3 is limited. In column 4 is the ratio of data to MC in the region 1.1 < W < 1.4 GeV. They are all about 1.1 which if attributed to the acceptance or luminosity being off would mean that the elastic data should be divided by 1.1 . The ratio of elastic data to MC is about near 1 except of parallel bottom. If one divides by the 1.1 of the elastic ratio then the elastic data is off by about 0.90 except for the parallel bottom which is 0.80.

Field/Cup ( packing fraction)	Data (C+He)/(NH3) 0.6 < W< 0.85	MC (C+He)/(N+He) 0.6 < W< 0.85	Inelastic data/MC 1.1 < W < 1.4	Elastic Data/MC 0.9 < W < 1.0
Perp/Top (57.3)	1.260 +- 0.013 (plot)	1.22 +- 0.004(plot)	1.11 (plot)	1.02 (plot)
Perp/Bottom (59.5)	1.209 +- 0.012 (plot)	1.21 +- 0.004 (plot)	1.12 (plot)	0.98 (plot)
Para/Top (53.2)	1.223 +- 0.009 (plot)	1.27 +- 0.004 (plot)	1.13 (plot)	0.97 (plot)
Para/Bottom (54.7)	1.256 +- 0.011 (plot)	1.25 +- 0.004 (plot)	1.09 (plot)	0.91 (plot)

Nitrogen asymmetry contribution:
Use a kumac to determine the nitrogen dilution factor from the Monte Carlo assuming a packing fraction of 55%. Plots of the 15N dilution factor for parallel and perpendicular target field. In the region 0.7 < W < 0.85 the dilution factor, Ndf, is about 70%. This dilution factor is for the nucleus cross section,but it needs to be the dilution factor for the nucleon cross section in that nucleus. So Ndf needs to be multiplied by the ratio of nucleon cross section in 15N to the nucleus cross section, Rxn . A plot of Rxn shows that below W = 0.85, on average Rxn = 0.092 .

The predicted corrected count asymmetry for the nitrogen is -1/3*Ap*(Pn/Ph) *Ndf *Rxn in which Pn is the nitrogen polarization, Ph is the hydrogen polarization and Ap is the asymmetry for a free proton. For the ratio of nitrogen polarization to hydrogen polarization, used

 Pn/abs(Ph) = -1*(0.312/abs(Ph)
+ 5.831e-02 + 8.935e-2*abs(Ph) + 8.685e-2*abs(Ph)^2)

for each run and took average weighted by the charge per run. When the W range is extended to 0.90 ,the measured count asymmetry for perpendicular has a large change. This is due to a tail of the elastic, so one can only include up to W = 0.85 GeV.

Field direction	Target	Pn/Ph	Predicted Corrected Count Asymmetry	Measured Corrected Count Asymmetry 0.7 < W< .85 abs(hsdelta)< 8.	Measured Corrected Count Asymmetry 0.7 < W< .90 abs(hsdelta) < 12.	Measured Corrected Count Asymmetry 0.7 < W< .85 abs(hsdelta) < 12.
Parallel	Top	-.165	0.0008	0.0036 +- 0.0046	0.0031 +- 0.0024	0.0026 +- 0.0031
Parallel	Bottom	-.164	0.0008	-0.0059 +- 0.0059	0.0050 +- .0030	0.0036 +- 0.0039
	Both			0.000 +- 0.0036	0.0038 +- 0.0018	0.0029 +- 0.0024

Perpendicular	Top	-.160	-0.0004	0.0098 +- 0.0057	0.0033 +- 0.0030	0.011 +- 0.0039
Perpendicular	Bottom	-.171	-0.0004	0.0091 +- 0.0054	0.0042 +- 0.0032	0.0098 +- 0.0042
	Both			0.0094 +- 0.0039	0.0037 +- 0.0022	0.0105 +- 0.0029

Use a kumac to determine the contribution from the nitrogen asymmetry to the total asymmetry. The final proton asymmetry , Ap = Atot - (Ndf/Hdf)*(Pn/Ph)*An in which Ndf is the nitrogen dilution factor, Hdf is the hydrogen dilution factor and An = -1/3*Ap or An is taken from data. Atot is the physics asymmetry and Ap is the final proton physics asymmetry . Using An from the data, plots of the nitrogen asymmetry contribution for parallel and perpendicular target fields for cut of abs(hsdelta)<12.

Field direction	Target	Measured Corrected Count Asymmetry 0.6 < W< .70 abs(hsdelta) < 12.	Measured Corrected Count Asymmetry 0.7 < W< .80 abs(hsdelta) < 12.	Measured Corrected Count Asymmetry 0.8 < W< .85 abs(hsdelta) < 12.	Measured Corrected Count Asymmetry 0.6 < W< .85 abs(hsdelta) < 12.
Parallel	Combined	0.0020 +- 0.0060	0.0066 +- 0.0034	0.0000 +- 0.0034	0.0031 +- 0.0022

Perp	Combined	-0.0180 +- 0.0068	0.0115 +- 0.004	0.0094 +- 0.0041	0.006 +- 0.0026

Field direction	Target	Measured Corrected Count Asymmetry 0.6 < W< .70 abs(hsdelta) < 12. abs(hsyptar)< .04 para use abs(hsxptar)< .12 perp use abs(hsxptar+.05)< .12	Measured Corrected Count Asymmetry 0.7 < W< .80 abs(hsdelta) < 12.	Measured Corrected Count Asymmetry 0.8 < W< .85 abs(hsdelta) < 12.	Measured Corrected Count Asymmetry 0.6 < W< .85 abs(hsdelta) < 12.
Parallel	Combined	0.0017 +- 0.0064	0.0072 +- 0.0036	-0.0002 +- 0.0037	0.0033 +- 0.0024

Perp	Combined	-0.0176 +- 0.0069	0.0114 +- 0.004	0.0092 +- 0.0041	0.0062 +- 0.0026

Decide to use the measured count asymmetry from region 0.6 < W < 0.85 .

Field Direction	Measured Nitrogen Physics Asymmetry	Predicted Nitrogen Physics Asymmetry
Parallel	0.0033/-.1645/.7/0.092 = -0.308 +- 0.223	-A(p)/3 = -0.072
Perp	0.0062/-.165/.7/0.092 = -0.574 +- 0.245	-A(p)/3 = 0.034

Comparison of C+He to N+He background :

Ran Monte Carlo with C+He target and NH3 target (55% packing fraction) for parallel and perpendicular field settings at p_central = 4.703 and with kumac determined the ratio of C+He yield to N+He+other background. The ratio is plotted here and compares the perpendicular and parallel field settings. The ratios are fitted and there is a small W dependence to the ratio. The fit formula are given in the table with the error on the coefficient given in parenthesis.

Target field	Fit to MC ratio ( Yield C+He)/( Yield NH3 background)
Parallel	1.281 (0.015) - 0.044*W (0.011)
Perpendicular	1.254 (0.014) - 0.027*W (0.012)

To compare to data , the kumac chains together the NH3 runs and C+He runs and scales the yield by the total charge and average tracking efficiency. The ratio of normalized C+He yield to the NH3 normalized yield is given in the table. Data and MC agree.

Target field	Plots	Ratio in region 0.7 < W< 0.85	MC ratio at W =0.77
Parallel	top versus bottom	1.22 +- 0.009 ( Top target) , 1.26 +- 0.010 ( Bottom target)	1.25
Perpendicular	top versus bottom	1.25 +- 0.011 ( Top target) , 1.22 +- 0.011 ( Bottom target)	1.23

Asymmetries in four electron scattering angle regions :

Pick four regions of the electron scattering angle which give equal counts.

Target field	Angular cuts (Average scattering angle)	Plots of Count asymmetry	Plots of Dilution factor	Plots of Physics Asymmetry versus scattering angle
Parallel	11.5 , 12.225, 12.775, 13.425, 15. (11.92,12.50,13.08,13.98)	parallel	parallel	parallel
Perpendicular	11.5, 12.4875, 13.0875, 13.8125, 16. ( 12.16,12.79,13.43,14.37)	perpendicular	perpendicular	perpendicular

Determine the counts asymmetry using the kumac. Used cut of abs(hsdelta)<12 and 0.8<(hsshtrk/hsp) . The count asymmetries are corrected for the target and beam polarization for the run. In addition, the top target runs are corrected by a factor of 1/1.019 and the bottom by 1/1.018 . The sign of the asymmetry is reversed in the kumac. ( Had problems with run 43801 so it was not used). Multiplied the bottom parallel counts asymmetry by 1.18 .
Used the kumac to extract the background shape for each angular region. The dilution factors were determined with the kumac by normalizing the background in the region of 0.7 < W < 0.85 .
Used the kumac to determined the physics asymmetry by combining the dilution factor and count asymmetries. Averaging over the region of 0.9 < W < 1.0 , plots of the physics asymmetry versus scattering angle are in the above table. For the perpendicular target field , since the top and bottom target asymmetries agreed with each other, they were averaged together. For the parallel target field, the top and bottom targets are shown separately.
Asymmetries in two electron scattering angle regions :

Pick two regions of the electron scattering angle which give equal counts.

Target field

Angular cuts
(average scattering angle)

Plots of
Count
asymmetry

Plots of
Dilution
factor

Plots of Physics
Asymmetry
versus W

Plots of Physics Asymmetry
versus scattering angle

Parallel

11.5 , 12.7625, 15.
(12.39,13.77)
(182.29,182.68)

parallel

15N corr ( from data)

parallel

Perpendicular

11.5, 13.0875, 16.
(12.31,13.70)
(171.6,168.24)

perp

15N corr (from data)	perp
15N corr (from data)	muGe/Gm plot

Determine the counts asymmetry using the kumac. Used cut of abs(hsdelta)<12 ,0.8<(hsshtrk/hsp), abs(hsyptar) < .04 and abs(hsxptar)< .12 ( parallel) or abs(hsxptar+0.05)<.12 (perp). The count asymmetries are corrected for the target and beam polarization for the run. In addition, the top target runs are corrected by a factor of 1/1.019 and the bottom by 1/1.018 . The sign of the asymmetry is reversed in the kumac. ( Had problems with run 43801 so it was not used). Multiplied the bottom parallel counts asymmetry by 1.18 .
Used the kumac to extract the background shape for each angular region. The dilution factors were determined with the kumac by normalizing the background in the region of 0.6 < W < 0.85 .
Used the kumac to determined the physics asymmetry by combining the dilution factor and count asymmetries. Averaging over the region of 0.9 < W < 1.0 , plots of the physics asymmetry versus scattering angle are in the above table. For the perpendicular target field , since the top and bottom target asymmetries agreed with each other, they were averaged together. For the parallel target field, the top and bottom targets are shown separately.
Used the kumac to determine the nitrogen contribution to the total asymmetry. The final proton asymmetry , Ap = Atot - (Ndf/Hdf)*(Pn/Ph)*An in which Ndf is the nitrogen dilution factor, Hdf is the hydrogen dilution factor and An = -1/3*Ap . Atot is the physics asymmetry and Ap is the final proton physics asymmetry . Plots of the nitrogen asymmetry contribution for parallel and perpendicular target fields.
Systematic Study
Systematic Error of Parallel Asymmetry
The largest systematic error is due to determination of the dilution factor. In the region 0.6 < W < 0.85 the normalization factor between the C+he data and the NH3 data is determined at the 0.3% level. The main concern is how well does the shape of the C+He data mimic the shape of the N+He background under the elastic peak in the NH3. In the region of 0.6 < W < 0.85, the ratio of C+He data ( normalized by a constant factor ) to the N+He data is constant, so at least in this W region the shape is understood. From the MC, one expects the ratio of C+He to N+He to change by 1% +- 0.3% from W = 0.77 to W =0.95. When determining the dilution factor, no change in the shape is assumed. Conservatively this leads to Del(asym)/asym = 1% .
The sensitivity of the elastic asymmetry to the ratio of Ge/Gm is very small Del(asym)/asym = 0.016*Del(Ge/Gm)/(Ge/gm). So even assuming a 10% error in Ge/Gm then gives a 0.2% error on the asymmetry.

The sensitivity of the elastic asymmetry to the kinematics is given in this file. The following is a table for parallel target field. The combined Del(asym)/asym = 0.3% all coming from the scattering angle uncertainty.

Variable	Del(Asym)/Del(Var)	Del(Var)	Del(Asym) or Del(Asym)/Asym
Scattering angle	0.0235 /deg or 0.0013 /mr	0.5 mr	0.0007 or 0.3%
Polar target angle	0.0013 /deg	0.1 deg (?)	0.0001 or 0.06%
Azimuthal target angle	0.0001/deg	1 deg (?)	0.0001 or 0.06%
Beam Energy	0.004 /GeV	0.003 GeV	0.00001 or 0.006%
Scattered Electron energy	0.005 /GeV	0.005 GeV	0.00003 or 0.018%

Systematic error of R = Ge/Gm from perpendicular target field.

Average the top and bottom targets asymmetries using the 15N asymmetry predicted assuming ( An = -Ap/3) then A = 0.0999 +- 0.0030 which gives R = 0.8876 +- 0.0267 . For this kinematics Del(R)/R = 0.9 Del(A)/A , so the systematic errors on the asymmetry from beam polarization,target polarization and dilution factor transfer directly to R. The sysstematic error on R is 4.6% . Formulas for the Del(R)/Del(var) are given in this file.

Variable	Del(R)/Del(Var)	Del(Var)	Del(R) or Del(R)/R
Scattering angle	0.0036 /mr	0.5 mr	0.0018 or 0.2%
Polar target angle	0.010 /deg	0.1 deg (?)	0.001 or 0.1%
Azimuthal target angle	0.004 /deg	1 deg (?)	0.004 or 0.45%
Beam Energy	0.017 /GeV	0.003 GeV	0.00005 or 0.005%
Scattered Electron energy	0.020 /GeV	0.005 GeV	0.0001 or 0.01%
Dilution factor		1%	1%
Beam Polarization		2.5% (abs)	3.6%
Target Polarization		2.9% (relative)	2.5%

Dependence of Asymmetries on Run Number and Target Polarization.
Elastic asymmetry as a function of run number for para and perp. The elastic asymmetry versus target polarization for para and perp. Determined the corrected asymmetry ( corrected for beam and target polarzation) in the combined regions of 0.8< W< 1.1 and 1.3 < W< 2.0 as a function of run number for para at 4.723, perp at 4.723, para at 4.095 and perp at 4.095 and as a function of target polarization for para at 4.723, perp at 4.723, para at 4.095 and perp at 4.095. Below is a table of the chi-squared/(number of points) when comparing the data to the average value of polarization. The perp settings look fine. The para settings have a high chi-sq/point = 1.7 for the bottom target for the "elastic" and "combined" setting at 4.723. For para at 4.095 the chi-sq/point drops to 0.92 .

Target Field	W region	Central Momentum	Chi-sq/point comparing average to value for each run	Chi-sq/point comparing average to value for each target polarization bin
Para	Elastic	4.723	1.1 (Bot) and 0.53 ( Top)	1.79 (Bot) and 1.25 ( Top)
Para	Combine	4.723	1.25 (Bot) and 1.02 ( Top)	1.61 (Bot) and 0.16 ( Top)
Para	1.3 < W < 2.0	4.095	0.37 (Bot) and 0.73 ( Top)	0.92 (Bot) and 0.92 ( Top)
Perp	Elastic	4.723	0.84 (Bot) and 1.03 ( Top)	1.09 (Bot) and 0.71 ( Top)
Perp	Combined	4.723	0.46 (Bot) and 0.62 ( Top)	0.41 (Bot) and 0.50 ( Top)
Perp	1.3 < W < 2.0	4.095	0.41 (Bot) and 0.61 ( Top)	0.30 (Bot) and 0.18 ( Top)

Go to : Dilution factor (updated May 5, 2005)

Corrected counts asymmetry:

Dilution factor:

Physics asymmetry:

Comparison of pass2a and pass3: (update March 2005)

Elastic cross section: (update Dec. 20, 2005)

Nitrogen asymmetry contribution:

Comparison of C+He to N+He background :

Asymmetries in four electron scattering angle regions :

Asymmetries in two electron scattering angle regions :