Elliptic flow of identified hadrons in Pb-Pb collisions at root(NN)-N-s=2.76 Tev


Abelev B., Adam J., Adamova D., Aggarwal M. M., Agnello M., Agostinelli A., ...More

JOURNAL OF HIGH ENERGY PHYSICS, vol.2015, no.6, 2015 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 2015 Issue: 6
  • Publication Date: 2015
  • Doi Number: 10.1007/jhep06(2015)190
  • Journal Name: JOURNAL OF HIGH ENERGY PHYSICS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Keywords: Collective flow, Heavy Ions, Particle correlations and fluctuations, HEAVY-ION COLLISIONS, QUARK-GLUON PLASMA, NUCLEUS-NUCLEUS COLLISIONS, PLUS AU COLLISIONS, AU+AU COLLISIONS, AZIMUTHAL ANISOTROPY, ROOT-S(NN)=200 GEV, ART., PHASE, FRAGMENTATION
  • Bursa Uludag University Affiliated: No

Abstract

The elliptic flow coefficient (v(2)) of identified particles in Pb-Pb collisions at root s(NN) = 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 correlation technique, using a pseudo-rapidity gap of |Delta eta| > 0.9 between the identified hadron under study and the reference particles. The v (2) is reported for pi(+/-), K-+/-, K-S(0), p+(p) over bar, phi, Lambda+(Lambda) over bar, Xi+(Xi) over bar (+) and Omega(-)+(Omega) over bar (+) in several collision centralities. In the low transverse momentum (p(T)) region, p(T) < 3 GeV/c, v(2)(p(T)) 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 pi (+/-) and the combined K-+/- and K-S(0) 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 v(2)(p(T)) for p+(p) over bar, phi, Lambda+(Lambda) over bar, Xi+(Xi) over bar (+). For transverse momentum values larger than about 3 GeV/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 p(T) > 3 GeV/c.