Centrality Dependence of the Charged-Particle Multiplicity Density at Midrapidity in Pb-Pb Collisions at √sNN=5.02 TeV
ALICE Collaboration. (2016). Centrality Dependence of the Charged-Particle Multiplicity Density at Midrapidity in Pb-Pb Collisions at √sNN=5.02 TeV. Physical Review Letters, 116 (22), 222302. doi:10.1103/PhysRevLett.116.222302
Published inPhysical Review Letters
Rak, Jan |
© 2016 CERN, for the ALICE Collaboration. Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License.
The pseudorapidity density of charged particles, dNch=dη, at midrapidity in Pb-Pb collisions has been measured at a center-of-mass energy per nucleon pair of √sNN=5.02 TeV. For the 5% most central collisions, we measure a value of 1943±54. The rise in dNch=dη as a function of √sNN is steeper than that observed in proton-proton collisions and follows the trend established by measurements at lower energy. The increase of dNch=dη as a function of the average number of participant nucleons, hNparti, calculated in a Glauber model, is compared with the previous measurement at √sNN=2.76 TeV. A constant factor of about 1.2 describes the increase in dNch=dη from √sNN=2,76 to 5.02 TeV for all centrality classes, within the measured range of 0%–80% centrality. The results are also compared to models based on different mechanisms for particle production in nuclear collisions.