Observation and studies of jet quenching in PbPb collisions at √sNN=2.76 TeV

Journal article

Jet production in PbPb collisions at a nucleon-nucleon center-of-mass energy of 2.76 TeV was studied with the Compact Muon Solenoid (CMS) detector at the LHC, using a data sample corresponding to an integrated luminosity of 6.7μb-1. Jets are reconstructed using the energy deposited in the CMS calorimeters and studied as a function of collision centrality. With increasing collision centrality, a striking imbalance in dijet transverse momentum is observed, consistent with jet quenching. The observed effect extends from the lower cutoff used in this study (jet pT=120 GeV/c) up to the statistical limit of the available data sample (jet pT≈210 GeV/c). Correlations of charged particle tracks with jets indicate that the momentum imbalance is accompanied by a softening of the fragmentation pattern of the second most energetic, away-side jet. The dijet momentum balance is recovered when integrating low transverse momentum particles distributed over a wide angular range relative to the direction of the away-side jet. © 2011 American Physical Society.

Authors: Chatrchyan, S; Khachatryan, V; Sirunyan, A; Tumasyan, A; Adam, W

• Journal: Physical Review C - Nuclear Physics
• Volume: 84
• Issue: 2
• Publication date: 2011-08-12
• DOI: 10.1103/PhysRevC.84.024906
• EISSN: 1089-490X
• ISSN: 0556-2813
• Language: English