Measurement of the centrality dependence of the charged particle pseudorapidity distribution in lead–lead collisions at √s[subscript NN] = 2.76 TeV with the ATLAS detector
Author(s)Taylor, Frank E.
MetadataShow full item record
The ATLAS experiment at the LHC has measured the centrality dependence of charged particle pseudorapidity distributions over |η|<2 in lead–lead collisions at a nucleon–nucleon centre-of-mass energy of √s[subscript NN] = 2.76 TeV. In order to include particles with transverse momentum as low as 30 MeV, the data were recorded with the central solenoid magnet off. Charged particles were reconstructed with two algorithms (2-point “tracklets” and full tracks) using information from the pixel detector only. The lead–lead collision centrality was characterized by the total transverse energy in the forward calorimeter in the range 3.2<|η|<4.9. Measurements are presented of the per-event charged particle pseudorapidity distribution, dN[subscript ch]/dη, and the average charged particle multiplicity in the pseudorapidity interval |η|<0.5 in several intervals of collision centrality. The results are compared to previous mid-rapidity measurements at the LHC and RHIC. The variation of the mid-rapidity charged particle yield per colliding nucleon pair with the number of participants is consistent with lower √s[subscript NN] results. The shape of the dN[subscript ch]/dη distribution is found to be independent of centrality within the systematic uncertainties of the measurement.
DepartmentMassachusetts Institute of Technology. Department of Physics
Physics Letters B
Aad, G., B. Abbott, J. Abdallah, A.A. Abdelalim, A. Abdesselam, O. Abdinov, B. Abi, et al. “Measurement of the Centrality Dependence of the Charged Particle Pseudorapidity Distribution in Lead–lead Collisions at √s[subscript NN] = 2.76 TeV with the ATLAS Detector.” Physics Letters B 710, no. 3 (April 2012): 363–382. © 2012 CERN
Final published version