May 22 – 28, 2011
Centre Bonlieu
Europe/Zurich timezone

Measurement of charged particle pseudorapidity density in PbPb collisions at sqrt(s_NN) = 2.76 TeV with the ATLAS detector at the LHC

May 23, 2011, 4:00 PM
Salle de l'Europe (Imperial Palace)

Salle de l'Europe

Imperial Palace

Parallel Global and collective dynamics Global and collective dynamics


Yujiao Chen (Columbia University)


Charged particle multiplicity is an important bulk observable for heavy ion collisions. It measures the global features of the medium produced and constrains the initial conditions of the system. It also provides an important test for dynamical model calculations which predict the dependence of multiplicity on centrality at RHIC and the LHC. We present the study of charged particle pseudorapidity density distributions over a broad range of pseudorapidity and centrality in Pb+Pb collisions at √sNN = 2.76 TeV with the ATLAS detector at LHC. The centrality dependence of the particle density near mid-rapidity scaled by the number of participating nucleon pairs (dNch/dη(|η| < 0.5)/(0.5Npart)) is presented. Comparisons with results from previous measurements are used to study the collision energy dependence. The pseudorapidity distributions measured over four units of pseudorapidity are compared with those of different collision systems and energies as well as dynamical models.

Primary author

Dr Toni Baroncelli (Physics Department University of ROMA TRE - Rome -Italy)

Presentation materials