Geometric Poisson distribution of photons produced in the ultrarelativistic hadronic collisions

Abstract

We show that the multiplicity distribution of photons produced with enhanced void probability in inelastic proton-proton collisions at sqrt{s} = 900 GeV, 2.76 TeV, and 7 TeV, measured at forward rapidities by the ALICE experiment at LHC, can be described by the geometric Poisson distribution. The traditionally used negative binomial distribution fails to reproduce the enhanced void probability and the shape of the modified combinants simultaneously. Our findings are relevant for the theoretical modeling of photon production processes in high-energy hadronic collisions.