Progress on the Single-Arm Compton Analysis M. H. Wood University of Massachusetts, Amherst

Consistency Study Analyze the single-arm channel of Compton scattering from p0 production runs. Extract the differential cross section for each run. Investigate for systematic deviations over time.

Standard Deviation in the Data 1st Run Range: s=1.4% 2nd Run Range: s=0.6% 3rd Run Range: s=0.9%

Spread in the Data 1st Run Range: c2/ndf = 8.3 2nd Run Range: 3rd Run Range: c2/ndf = 6.6

Double-Arm Compton Analysis Motivation: In order to understand the single-arm Compton analysis, analyze the well-understood double-arm Compton analysis. I followed the event selection in Yelena’s Analysis note. My deviations: Applied the veto to each cluster. Applied a cut on the photon angle (0.5o<q<0.9o).

Yield Extraction Fit the Df distribution with two gaussian shapes (one for the peak and one for the background). Make fits for each T-counter.

Comparison of Different Analyses Single-arm, p0 run Single-arm, Compton run Double-arm, Compton run Where is the difference? Y - yield (different) NT - # target centers (same) Ng – photon flux (same) DW – solid angle (same) – geometrical acceptance (same) With the single- and double-arm analyses of the same run, I can isolate differences in Y. T-counter ID