# 2012 Collins Plots Updates - Plotting vs. xF

To show the agreement with Jim's analysis, the first plots show the xF < 0 plots when Collins is plotted versus Z. These are shown for both pT < 10 GeV/c (LEFT) and pT > 10 GeV/c (RIGHT)

Figure 1: Collins asymmetry as a function of Z for xF < 0. These are for both pT < 10 GeV/c (LEFT) and pT > 10 GeV/c (RIGHT)

Fitting these with a 0th order polynomial, we have:

 pT < 10 GeV/c pT > 10 GeV/c Average Stat. Error Average Stat. Error pi+ 2.28763e-05 0.000344812 pi+ 0.00141909 0.000504303 pi- -0.000556444 0.000351055 pi- -0.00114952 0.000508507

Binning yields in bins of xF allows for plotting the asymmetry for forward and backward scattered jets with respect to the polarized beam on the same plot. For pT > 10 GeV/c and pT < 10 GeV/c are shown below

Figure 2: Collins asymmetry as a function of xF for both pT < 10 GeV/c (LEFT) and pT > 10 GeV/c (RIGHT)

We are still trying to understand why the plot doesn't smoothly start to transition to zero for xF < 0, rather it seems to increase and then start a trend toward zero.

These can be split further into bins of z and jT. The bins I chose, which are purely experimental at this point and can be changed later, are:
0 < z < 0.2, 0.2 < z < 0.5, 0.5 < z < 1
0 < jT < 0.375, 0.375 < jT < 4.5

I will show these next time! The xF bins need to be adjusted for the decreasing statistics at higher z and jT. I will play with it this week to get a better set of plots, and I will also (finally) look at the eta bins that Jim has been looking at and give a double check on those numbers.

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