Jet momentum dependence of jet quenching in PbPb collisions at root s(NN)=2.76 TeV

Abstract

Dijet production in PbPb collisions at a nucleon-nucleon center-of-mass energy of 2.76 TeV is studied with the CMS detector at the LHC. A data sample corresponding to an integrated luminosity of 150 mu b(-1) is analyzed. Jets are reconstructed using combined information from tracking and calorimetry, using the anti-k(T) algorithm with R = 0.3. The dijet momentum balance and angular correlations are studied as a function of collision centrality and leading jet transverse momentum. For the most peripheral PbPb collisions, good agreement of the dijet momentum balance distributions with pp data and reference calculations at the same collision energy is found, while more central collisions show a strong imbalance of leading and subleading jet transverse momenta attributed to the jet-quenching effect. The dijets in central collisions are found to be more unbalanced than the reference, for leading jet transverse momenta up to the highest values studied. (C) 2012 CERN. Published by Elsevier B.V. All rights reserved.