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

Abelev B., Adam J., Adamova D., Adare A. M., Aggarwal M. M., Rinella G. A., ...More

PHYSICS LETTERS B, vol.720, no.1-3, pp.52-62, 2013 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 720 Issue: 1-3
  • Publication Date: 2013
  • Doi Number: 10.1016/j.physletb.2013.01.051
  • Journal Name: PHYSICS LETTERS B
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.52-62
  • Bursa Uludag University Affiliated: No


The inclusive transverse momentum (p(T)) distributions of primary charged particles are measured in the pseudo-rapidity range vertical bar eta vertical bar <0.8 as a function of event centrality in Pb-Pb collisions at root S-NN = 2.76 TeV with ALICE at the LHC. The data are presented in the p(T) range 0.15 < p(T) <50 GeV/c for nine centrality intervals from 70-80% to 0-5%. The results in Pb-Pb are presented in terms of the nuclear modification factor R-AA using a pp reference spectrum measured at the same collision energy. We observe that the suppression of high-p(T) particles strongly depends on event centrality. The yield is most suppressed in central collisions (0-5%) with R-AA approximate to 0.13 at p(T) = 6-7 GeV/c. Above p(T) = 7 GeV/c, there is a significant rise in the nuclear modification factor, which reaches R-AA approximate to 0.4 for p(T) > 30 GeV/c. In peripheral collisions (70-80%), only moderate suppression (R-AA approximate to 0.6-0.7) and a weak p(T) dependence is observed. The measured nuclear modification factors are compared to other measurements and model calculations. (C) 2013 CERN. Published by Elsevier B.V. All rights reserved.