TWOGEN—a simple Monte Carlo generator for two-photon reactions

TWOGEN samples the transverse-transverse luminosity function for real and virtual photons, then weights events with any user-supplied cross section σTT(γγ → X) in a “hit or miss” sampling, using a simple method to avoid the singularity at the minimum electron angle ϑmin=0. Events within defined kinematic limits are accepted and the corresponding cross section is estimated, together with the effective luminosity of the run. Functions implemented …