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.

Journal article

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.

Authors: Aad, G; Abbott, B; Abdallah, J; Abdelalim, A; Abdesselam, A

• Publication status: Published
• Journal: Physical Review Letters
• Volume: 105
• Issue: 25
• Pages: 252303
• Publication date: 2010-12-01
• DOI: 10.1103/physrevlett.105.252303
• EISSN: 1079-7114
• ISSN: 0031-9007
• Language: English
• Keywords: ATLAS Collaboration