Centrality dependence of the pseudorapidity density distribution for charged particles in Pb–Pb collisions at sNN=5.02 TeV

Summary, in English

We present the charged-particle pseudorapidity density in Pb–Pb collisions at sNN=5.02 TeV in centrality classes measured by ALICE. The measurement covers a wide pseudorapidity range from −3.5 to 5, which is sufficient for reliable estimates of the total number of charged particles produced in the collisions. For the most central (0–5%) collisions we find 21400±1300, while for the most peripheral (80–90%) we find 230±38. This corresponds to an increase of (27±4)% over the results at sNN=2.76 TeV previously reported by ALICE. The energy dependence of the total number of charged particles produced in heavy-ion collisions is found to obey a modified power-law like behaviour. The charged-particle pseudorapidity density of the most central collisions is compared to model calculations — none of which fully describes the measured distribution. We also present an estimate of the rapidity density of charged particles. The width of that distribution is found to exhibit a remarkable proportionality to the beam rapidity, independent of the collision energy from the top SPS to LHC energies. © 2017 The Author(s)

• Author: J. Adam; D. Adamova; M.M Aggarwal; G Aglieri Rinella; M. Agnello; N Agrawal; Peter Christiansen; Martin Ljunggren; Anders Oskarsson; Tuva Richert; David Silvermyr; Evert Stenlund; Vytautas Vislavicius
• Department/s: Particle and nuclear physics
• Publishing year: 2017
• Language: English
• Pages: 567-577
• Publication/Series: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
• Volume: 772
• Links: http://dx.doi.org/10.1016/j.physletb.2017.07.017
• Document type: Journal article
• Publisher: Elsevier
• Topic: Subatomic Physics
• Status: Published
• ISBN/ISSN/Other: ISSN: 0370-2693