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

Abelev, B. and Adam, J. and Adamová, D. and Aggarwal, M. M. and Agnello, M. and Barnaföldi, Gergely Gábor and Bencédi, Gyula and Berényi, Dániel and Boldizsár, László and Dénes, Ervin and Hamar, Gergő and Kiss, Gábor and Varga-Kőfaragó, Mónika and Lévai, Péter and Oláh, László and Pochybova, Sona (2015) Elliptic flow of identified hadrons in Pb–Pb collisions at √sNN=2.76 TeV. JOURNAL OF HIGH ENERGY PHYSICS, 2015 (6). ISSN 1126-6708

Preview

Text 1405.4632.pdf Available under License Creative Commons Attribution. Download (1MB) | Preview

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 LHC. The results were obtained with the Scalar Product method, a two-particle correlation 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±, K0 S, p+p, φ , Λ+Λ, Ξ−+Ξ+ and Ω−+Ω+ in several collision centralities. In the low transverse momentum (pT) region, pT < 2 GeV/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 K are described fairly well by hydrodynamical 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 3 GeV/c, particles tend to group according to their type, i.e. mesons and baryons. However, the experimental data at the LHC exhibit deviations from the number of constituent quark (NCQ) scaling at the level of ±20% for pT > 3 GeV/c.

Actions (login required)

Edit Item