Measurement of isolated photon production in pp and PbPb collisions at sNN=2.76 TeV

Chatrchyan S., Khachatryan V., Sirunyan A., Tumasyan A., Adam W., Bergauer T., ...More

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, vol.710, no.2, pp.256-277, 2012 (SCI-Expanded) identifier identifier identifier


Isolated photon production is measured in proton-proton and lead-lead collisions at nucleon-nucleon centre-of-mass energies of 2.76 TeV in the pseudorapidity range |η|<1.44 and transverse energies E T between 20 and 80 GeV with the CMS detector at the LHC. The measured E T spectra are found to be in good agreement with next-to-leading-order perturbative QCD predictions. The ratio of PbPb to pp isolated photon E T-differential yields, scaled by the number of incoherent nucleon-nucleon collisions, is consistent with unity for all PbPb reaction centralities. © 2012 CERN.