COMPTON ANALYSIS STATUS Selection Criteria Extraction Procedure Line Shape Yield Fits Total Cross Section Forward Cross Section Systematic Uncertainties Time Stability Conclusions

Event Selection

Event Selection

Event Selection

Background Model

Event Selection

Event Selection

Line Shape Yield Fits

The Procedure Total Cross Section Forward Cross Section

Total Cross Section

Forward Cross Section

Systematic Uncertainties (Average Values) Photon Flux 1.0% Target Thickness/Composition 0.05% Coincidence Timing Cut 0.05% Coplanarity Cut 0.078% Radiative Tail Cut 0.045% Geometric Cuts 0.60% Background Subtraction 0.72% Yield Fit Stability 0.063% HyCal Response Function 0.5% TOTAL < 1.5%

Time Stability

Conclusions Cross Section extracted with ~1.65% total error Background Simulation needed to reduce systematics Differential Cross Section needed for publication