Observation of a Centrality-Dependent Dijet Asymmetry in Lead-Lead Collisions at sqrt(S(NN))= 2.76 TeV with the ATLAS Detector at the LHC

G. Aad...[et al.], Mogens Dam, John Renner Hansen, Jørgen Beck Hansen, Jørn Dines Hansen, Peter Henrik Hansen, Morten Dam Jørgensen, Esben Bryndt Klinkby, Stefania Xella

Research output: Contribution to journalJournal articleResearchpeer-review

677 Citations (Scopus)

Abstract

By using the ATLAS detector, observations have been made of a centrality-dependent dijet asymmetry in the collisions of lead ions at the Large Hadron Collider. In a sample of lead-lead events with a per-nucleon center of mass energy of 2.76 TeV, selected with a minimum bias trigger, jets are reconstructed in fine-grained, longitudinally segmented electromagnetic and hadronic calorimeters. The transverse energies of dijets in opposite hemispheres are observed to become systematically more unbalanced with increasing event centrality leading to a large number of events which contain highly asymmetric dijets. This is the first observation of an enhancement of events with such large dijet asymmetries, not observed in proton-proton collisions, which may point to an interpretation in terms of strong jet energy loss in a hot, dense medium.
Original languageEnglish
JournalPhysical Review Letters
Volume105
Issue number25
Pages (from-to)252303
Number of pages18
ISSN0031-9007
DOIs
Publication statusPublished - 13 Dec 2010

Cite this