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

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 t...

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Bibliographic Details
Main Authors: Chatrchyan, S, Khachatryan, V, Sirunyan, A, Tumasyan, A, Adam, W, Bergauer, T, Dragicevic, M, Erö, J, Fabjan, C, Friedl, M, Frühwirth, R, Ghete, V, Hammer, J, Hoch, M, Hörmann, N, Hrubec, J, Jeitler, M, Kiesenhofer, W, Knapitsch, A, Krammer, M, Liko, D, Mikulec, I, Pernicka, M, Rahbaran, B, Rohringer, C
Format: Journal article
Published: 2012
Description
Summary: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.