Photon multiplicity measurements: From SPS to RHIC and LHC

摘要

Results from the photon multiplicity measurements using a ???ne granularity pre-shower photon multiplicity detector (PMD) at CERN SPS are discussed. These include study of pseudorapidity distributions of photons, scaling of photon multiplicity with number of participating nucleons, centrality dependence of $langle p_{T} angle$ of photons, event-by-event ???uctuations in photon multiplicity and localised charged-neutral ???uctuations. Basic features of the PMD to be used in STAR experiment at RHIC and in ALICE experiment at LHC are also discussed.