Observation of a centrality-dependent dijet asymmetry in lead-lead collisions at √sNN=2.76 TeV with the ATLAS detector at the LHC

Article English OPEN
Farrington, Sinead ; HASH(0x561a136eafa0) (2010)
  • Publisher: American Physical Society
  • Related identifiers: doi: 10.1103/PhysRevLett.105.252303
  • Subject: QC
    arxiv: High Energy Physics::Phenomenology | Nuclear Experiment | High Energy Physics::Experiment

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.
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