1. Radiative Corrections to the Electron Compton Scattering Cross Section
Liping Gan
University of North Carolina Wilmington
March 18, 2006

2. Single Compton Scattering
Cross section is first calculated by Klein and Nishina in 1929:

3. Virtual-Photon Radiative Correction
Calculated by Brown and Feynman in 1952:
Contribution to the measurement result is independent of experimental setup.

4. Double Compton scattering
Contributions to the measurement depend on the experimental setup and analysis procedures. There are two cases in our experiment:
Case (a), Unsymmetrical photon pair with an undetected photon’s energy within the HYCAL energy resolution.
Case (b), Both scattering photons have relatively large energies, however, they hit on the HYCAL with a small opening angle which are misidentified as a single cluster by HYCAL.

5. Calculation based on the Work of Meister and Yennie
Keep up to logarithmic order.
Consider external current only.
Include only the case (a) in the double Compton contribution.
Estimated error is at ~2%.

7. Work in Process
Using high-energy approximations, and neglect terms of the order of 1/Eγ.
Complete calculation which includes both case (a) and (b) in double Compton scattering
The program is ready to run.
Missing information: the minimum opening angle of two clusters can be distinguished by HYCAL.