Measurement of the centrality dependence of charged particle spectra and RCP in lead-lead collisions at √sNN = 2.76 TeV with the ATLAS detector at the LHC

Lead-lead collisions at the LHC provide an opportunity to study the properties of strongly interacting matter at the highest temperatures and energy densities ever achieved in the lab- oratory. In particular, jets are expected to be strongly quenched in the presence of the hot, dense medium, as illustrated by the centrality dependence of the dijet asymmetry already measured by ATLAS. Evidence of jet quenching can also be obtained from a measurement of inclusive charged particles at large transverse momentum, and in particular comparisons of spectral shapes between central and peripheral collisions. This note presents charged particle spectra as a function of centrality and rapidity, corrected for efficiency, fake tracks, secondaries and resolution. Using these, the ratio of scaled central to peripheral charged particle yields, RCP, is measured as a function of pT, centrality and pseudorapidity.