Single photon reconstruction efficiency
From GlueXWiki
Comparison of single photon reconstruction efficiency as a function of generated polar angle between old and new detector design. Photons were generated in full azimuth from the center of the target with energies from 0.05 to 5.0 GeV (in steps of 100 MeV). MC information provided that the single cluster was reconstructed from the photon that did not convert before the FCAL. Significant improvement can be seen between 9 and 10 degrees and not very much between 10 and 11.
Comparison between the FDC option 1 and option 2 of new design.
Question: what happened at 4 degree?
