We present the charged-particle pseudorapidity density in Pb–Pb collisions at \sqrt{s_NN} = 5.02TeV 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\pm1300, while for the most peripheral (80–90%) we find 230\pm38. This corresponds to an increase of (27\pm4)% over the results at \sqrt{s_NN} = 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.

Centrality dependence of the pseudorapidity density distribution for charged particles in Pb–Pb collisions at \sqrt{s} = 5.02 TeV

F. Barile;D. Colella
Membro del Collaboration Group
;
M. Mazzilli
Membro del Collaboration Group
;
G. Volpe
Membro del Collaboration Group
;
2017-01-01

Abstract

We present the charged-particle pseudorapidity density in Pb–Pb collisions at \sqrt{s_NN} = 5.02TeV 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\pm1300, while for the most peripheral (80–90%) we find 230\pm38. This corresponds to an increase of (27\pm4)% over the results at \sqrt{s_NN} = 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.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11586/489100
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 91
  • ???jsp.display-item.citation.isi??? ND
social impact