StEemcGammaFilter is the Pythia level EEMC gamma filter.

The code is available at STAR/cvs: StEemcGammaFilter.h / StEemcGammaFilter.cxx
Basic algo description:

• Loop over particles and search for the ones with energy higher than threshold and falls into the fiducial (in rapidity) volume
• Search for clusters around each seed include tracks in eta and phi (detector Eta and Phi) space within the cone radious

Algo parameters:

mConeRadius - eta-phi cluster cone radius
mSeedThreshold - seed track threshold
mClusterThreshold - track cluster threshold
mEtaLow - lowerst rapidity cut
mEtaHigh - highest rapidity cut
mMaxVertex - vertex cut

Other parameters:

mCalDepth - calorimeter depth at which tracks are extrapolated
mMinPartEnergy - minimum particle energyto be included in the cluster
mHadronScale - down scale factor for hadrons (be careful when playing with this) No scaling by default
mFilterMode - filter mode: 0 - test mode (no event rejection), 1 - filter reject events
mPrintLevel - print level (0 - no output, 1 or 2 print some logs)