6533b7dcfe1ef96bd1271b69
RESEARCH PRODUCT
Observation of a Centrality‐Dependent Dijet Asymmetry in Lead‐Lead Collisions at √SNN= 2.76 TeV with the ATLAS Detector at LHC
Atlas CollaborationJosé Salt CairolsJuan Antonio Valls FerrerSusana Cabrera UrbánMaría Victoria Castillo GiménezSalvador Martí GarcíaMiguel Villaplana PérezAntonio Ferrer SoriaJuan A. Fuster VerdúCarmen García GarcíaSantiago González De La HozYesenia Hernández JiménezEmilio Higón RodríguezAdrián Irles QuilesEduardo Ros MartínezCarlos Lacasta LlácerVasiliki MitsouVicente Lacuesta MiquelMaría José Costa Mezquitasubject
Acceleradors de partículesHigh Energy Physics::ExperimentNuclear ExperimentDetectors de radiaciódescription
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 underlying event is measured and subtracted event-by-event, giving estimates of jet transverse energy above the ambient background. The transverse energies of dijets in opposite hemispheres is 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, and which may point to an interpretation in terms of strong jet energy loss in a hot, dense medium.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2010-01-01 |