The elliptic flow coefficient (v2) of identified particles in Pb-Pb collisions at √sNN = 2.76 TeV was measured with the ALICE detector at the Large Hadron Collider (LHC). The results were obtained with the Scalar Product method, a two-particle corre- lation technique, using a pseudo-rapidity gap of |∆η| > 0.9 between the identified hadron under study and the reference particles. The v2 is reported for π±, K±, K0S, p+p, φ, Λ+Λ, Ξ−+Ξ+ and Ω−+Ω+ in several collision centralities. In the low transverse momentum (pT) region, pT < 3GeV/c, v2(pT) exhibits a particle mass dependence consistent with elliptic flow accompanied by the transverse radial expansion of the system with a common velocity field. The experimental data for π± and the combined K± and K0S results, are described fairly well by hydrodynamic calculations coupled to a hadronic cascade model (VISHNU) for central collisions. However, the same calculations fail to reproduce the v2(pT) for p+p, φ, Λ+ Λ and Ξ−+Ξ+. For transverse momentum values larger than about 3GeV/c, particles tend to group according to their type, i.e. mesons and baryons. The present measurements exhibit deviations from the number of constituent quark (NCQ) scaling at the level of ±20% for pT > 3 GeV/c.

Elliptic flow of identified hadrons in Pb-Pb collisions at √sNN = 2.76 TeV

CAMERINI, Paolo;FRAGIACOMO, ENRICO;LEA, RAMONA;LUPARELLO, GRAZIA;MARGAGLIOTTI, GIACOMO;PIANO, STEFANO;RUI, RINALDO;Zaccolo, V.;
2015

Abstract

The elliptic flow coefficient (v2) of identified particles in Pb-Pb collisions at √sNN = 2.76 TeV was measured with the ALICE detector at the Large Hadron Collider (LHC). The results were obtained with the Scalar Product method, a two-particle corre- lation technique, using a pseudo-rapidity gap of |∆η| > 0.9 between the identified hadron under study and the reference particles. The v2 is reported for π±, K±, K0S, p+p, φ, Λ+Λ, Ξ−+Ξ+ and Ω−+Ω+ in several collision centralities. In the low transverse momentum (pT) region, pT < 3GeV/c, v2(pT) exhibits a particle mass dependence consistent with elliptic flow accompanied by the transverse radial expansion of the system with a common velocity field. The experimental data for π± and the combined K± and K0S results, are described fairly well by hydrodynamic calculations coupled to a hadronic cascade model (VISHNU) for central collisions. However, the same calculations fail to reproduce the v2(pT) for p+p, φ, Λ+ Λ and Ξ−+Ξ+. For transverse momentum values larger than about 3GeV/c, particles tend to group according to their type, i.e. mesons and baryons. The present measurements exhibit deviations from the number of constituent quark (NCQ) scaling at the level of ±20% for pT > 3 GeV/c.
http://link.springer.com/journal/13130
File in questo prodotto:
File Dimensione Formato  
Elliptic flow of identified hadrons in Pb-Pb collisions at √sNN = 2.76 TeV.pdf

accesso aperto

Descrizione: pdf articolo versione editoriale
Tipologia: Documento in Versione Editoriale
Licenza: Digital Rights Management non definito
Dimensione 1.71 MB
Formato Adobe PDF
1.71 MB Adobe PDF Visualizza/Apri

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/11368/2866009
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 99
  • ???jsp.display-item.citation.isi??? 144
social impact