Suppression of charged particle production at large transverse momentum in central Pb-Pb collisions at root s(NN)=2.76 TeV


Aamodt K., Abrahantes Quintana A., Adamova D., Adare A. M., Aggarwal M. M., Rinella G. A., ...More

PHYSICS LETTERS B, vol.696, no.1-2, pp.30-39, 2011 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 696 Issue: 1-2
  • Publication Date: 2011
  • Doi Number: 10.1016/j.physletb.2010.12.020
  • Journal Name: PHYSICS LETTERS B
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.30-39
  • Keywords: R-AA, Nuclear modification factor, Pb-Pb, root s(NN)=2.76 TeV, ALICE, LHC, QUARK-GLUON PLASMA, PERSPECTIVE, SATURATION
  • Bursa Uludag University Affiliated: No

Abstract

Inclusive transverse momentum spectra of primary charged particles in Pb-Pb collisions at root s(NN) = 2.76 TeV have been measured by the ALICE Collaboration at the LHC. The data are presented for central and peripheral collisions, corresponding to 0-5% and 70-80% of the hadronic Pb-Pb cross section. The measured charged particle spectra in |eta| < 0.8 and 0.3 < p(T) < 20 GeV/c are compared to the expectation in pp collisions at the same root s(NN), scaled by the number of underlying nucleon-nucleon collisions. The comparison is expressed in terms of the nuclear modification factor R-AA. The result indicates only weak medium effects (R-AA approximate to 0.7) in peripheral collisions. In central collisions, R-AA reaches a minimum of about 0.14 at p(T) = 6-7 GeV/c and increases significantly at larger p(T). The measured suppression of high-p(T) particles is stronger than that observed at lower collision energies, indicating that a very dense medium is formed in central Pb-Pb collisions at the LHC. (C) 2010 CERN. Published by Elsevier B.V. All rights reserved.