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

Authors

• CMS Collaboration
• Ekaterina Avdeeva, University of Nebraska-LincolnFollow
• Kenneth A. Bloom, University of Nebraska-LincolnFollow
• S. Bose, University of Nebraska-LincolnFollow
• Jamila Butt, University of Nebraska-Lincoln
• Daniel R. Claes, University of Nebraska-LincolnFollow
• Aaron Dominguez, University of Nebraska-LincolnFollow
• Michael Eads, University of Nebraska-LincolnFollow
• P. Jindal, University of Nebraska-Lincoln
• J. Keller, University of Nebraska-LincolnFollow
• Ilya Kravchenko, University of Nebraska-LincolnFollow
• Jose Lazo-Flores, University of Nebraska-LincolnFollow
• Helena Malbouisson, University of Nebraska-Lincoln
• Sudhir Malik, University of Nebraska-LincolnFollow
• Gregory Snow, University of Nebraska-LincolnFollow

Document Type

Article

Date of this Version

2012

Citation

Physics Letters B 710 (2012) 256–277; doi:10.1016/j.physletb.2012.02.077

Abstract

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.