### Measurement of isolated-photon+jet correlations in PbPb collisions at $\sqrt{s} = 2.76\:\mathrm{TeV}$ with CMSMeasurement of isolated-photon+jet correlations in PbPb collisions at $\sqrt{s} = 2.76\:\mathrm{TeV}$ with CMS

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 Author Lai, Yue Shi Source CERN Document Server Content type Text File Format PDF Date Created 2012-09-24 Language English
 Subject Domain (in DDC) Natural sciences & mathematics ♦ Physics ♦ Modern physics ♦ Technology ♦ Engineering & allied operations ♦ Applied physics Subject Keyword HeavyIons ♦ Detectors and Experimental Techniques Abstract A measurement of the transverse momentum balance in isolated-photon+jet pairs in PbPb collisions is described. The analysis is performed using a dataset recorded by the CMS experiment at the LHC from PbPb collisions at a $\sqrt{s_{NN}} = 2.76\:\mathrm{TeV}$, corresponding to an integrated luminosity of $150\:\mathrm{\mu b}^{-1}$. For events containing an isolated photon with $p_T^\gamma > 60\:\mathrm{GeV}/c$ and an associated jet with $p_T^\mathrm{Jet} > 30\:\mathrm{GeV}/c$, the photon+jet transverse momentum balance is studied as a function of collision centrality and compared to pp data and PYTHIA calculations. Using the isolated photon as the probe of the partonic energy at production, this measurement allows an unbiased characterization of the in-medium parton energy loss. With increasing collision centrality, a significant decrease in the ratio $p_T^\mathrm{Jet}/p_T^\gamma$ relative to the pp reference is observed. Description Presented at: 5th international conference on Hard and Electromagnetic probes of High Energy Nuclear Collisions, Cagliari, Italy, 27 May - 1 Jun 2012Collaboration with: CMS Learning Resource Type Article Publisher Date 2012-01-01 Rights License Preprint: (License: CC-BY-4.0) Page Count 5