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

0369949 - FZÚ 2012 RIV US eng J - Journal Article
Aad, G. - Abbott, B. - Abdallah, J. - Chudoba, Jiří - Gallus, Petr - Gunther, Jaroslav - Havránek, Miroslav - Hruška, I. - Juránek, Vojtěch - Kepka, Oldřich - Kupčo, Alexander - Kůs, Vlastimil - Kvasnička, Jiří - Lipinský, L. - Lokajíček, Miloš - Marčišovský, Michal - Mikeštíková, Marcela - Myška, Miroslav - Němeček, Stanislav - Panušková, M. - Růžička, Pavel - Schovancová, Jaroslava - Šícho, Petr - Staroba, Pavel - Taševský, Marek - Tic, Tomáš - Valenta, J. - Vrba, Václav
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.
Physical Review Letters. Roč. 105, č. 25 (2010), "252303-1"-"252303-5". ISSN 0031-9007. E-ISSN 1079-7114
R&D Projects: GA MŠMT LC527; GA MŠMT LA08032; GA MŠMT LA08015
Institutional research plan: CEZ:AV0Z10100502
Keywords : jet: pair production * jet: transverse energy * jet: energy loss * calorimeter:hadronic * jet: angular distribution * ATLAS * underlying event
Subject RIV: BF - Elementary Particles and High Energy Physics
Impact factor: 7.621, year: 2010

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.
Permanent Link: http://hdl.handle.net/11104/0203889