1. Pair Production at PrimEx

2. Event Selection

3. Event Selection

4. Event Selection

5. Event Selection

6. Event Selection

7. GEANT4 Simulation

8. GEANT4 Simulation

9. GEANT4 Simulation

10. GEANT4 Simulation

11. GEANT4 Simulation

12. GEANT4 Simulation

13. GEANT4 Simulation

14. GEANT4 Simulation

15. GEANT4 Simulation

16. GEANT4 Simulation

17. GEANT4 Simulation

18. Yield Extraction

19. Yield Extraction

20. Yield Extraction

21. Yield Extraction

22. Yield Extraction

23. Yield Extraction

24. Theoretical Considerations
Bethe-Heitler mechanism of pair production on the nucleus with screening effects due to atomic electrons and Coulomb distortion
Pair production off atomic electrons, considering excitation of all atomic states and correlation effects due to presence of other electrons and the nucleus
Radiative corrections (of order ) (i) virtual-photon loops and (ii) real-photon process like  + →e+ + e- +  + 
Nuclear incoherent contribution,  + p →e+ + e- + p
Nuclear coherent contribution (VCS),  + →* + →e+ + e- + 

25. Theoretical Considerations

26. Theoretical Considerations

27. Cross Section

28. Cross Section

29. Cross Section

30. Preliminary Error Estimate
Statistics (per bin) < 2.35%
Number of Carbon atoms 0.05%
Photon flux
Statistics <0.34%
Systematic ~0.97% (assuming no leakage)
Backrgound subtraction ~0.50%
HyCal Resolution <0.10%
HyCal Calibration ?%
Multiphoton Events ?%
TOTAL (per bin) %(stat.) 1.1%(sys.)
-(the ? Still need to be added in)

31. Problems

32. Problems