Hadronic vs EM Response FPD/FMS Small Cells

 I have added a hadronic list to Geant4 to compare pi+ and pi0 response of the FPD/FMS.

 I am using a photo-cathode that is embeded at the end of the Pb. Glass cell (no gap).

STAR/files/userfiles/1651/file/PbGlassShape/GeantHad1.pdf

The posting by Chris does a related study with gap/cookie between Pb/Glass and phototube.

The conclusion from this note is that it is the Cerenkov peak that produces the large hadronic response and cutting anglular response both improves the resolutin for EM signals and reduces the large energy hadronic response.

 

Note: In this model, the minimum ionizing peak nearly all shows up in the Cerenkov peak, at large angles.