Higher harmonic flow coefficients of identified hadrons in Pb-Pb collisions at root sNN=2.76 TeV

0472555 - ÚJF 2017 RIV US eng J - Journal Article
Adam, J. - Adamová, Dagmar - Bielčík, J. - Bielčíková, Jana - Broz, M. - Čepila, J. - Contreras, J. G. - Eyyubova, G. - Ferencei, Jozef - Horák, D. - Křížek, Filip - Kučera, Vít - Mareš, Jiří A. - Petráček, V. - Pospíšil, Jan - Šumbera, Michal - Vaňát, Tomáš - Závada, Petr … Total 1004 authors
Higher harmonic flow coefficients of identified hadrons in Pb-Pb collisions at root sNN=2.76 TeV.
Journal of High Energy Physics. Roč. 2016, č. 9 (2016), č. článku 164. ISSN 1029-8479. E-ISSN 1029-8479
R&D Projects: GA MŠMT(CZ) LG13031
Institutional support: RVO:68378271 ; RVO:61389005
Keywords : ALICE collaboration * Hadron-Hadron scattering
Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders; BF - Elementary Particles and High Energy Physics (FZU-D)
Impact factor: 6.063, year: 2016

The elliptic, triangular, quadrangular and pentagonal anisotropic flow coefficients for pi(+/-), K-+/- and p+p in Pb-Pb collisions at root sNN = 2.76TeV were measured with the ALICE detector at the Large Hadron Collider. The results were obtained with the Scalar Product method, correlating the identified hadrons with reference particles from a different pseudorapidity region. Effects not related to the common event symmetry planes (non-flow) were estimated using correlations in pp collisions and were subtracted from the measurement. The obtained flow coefficients exhibit a clear mass ordering for transverse momentum (pT) values below approximate to 3 GeV/c. In the intermediate pT region (3 < pT < 6 GeV/c), particles group at an approximate level according to the number of constituent quarks, suggesting that coalescence might be the relevant particle production mechanism in this region. The results for pT < 3 GeV/c are described fairly well by a hydrodynamical model (iEBE-VISHNU) that uses initial conditions generated by A Multi-Phase Transport model (AMPT) and describes the expansion of the fireball using a value of 0.08 for the ratio of shear viscosity to entropy density (eta/s), coupled to a hadronic cascade model (UrQMD). Finally, expectations from AMPT alone fail to quantitatively describe the measurements for all harmonics throughout the measured transverse momentum region. However, the comparison to the AMPT model highlights the importance of the late hadronic rescattering stage to the development of the observed mass ordering at low values of pT and of coalescence as a particle production mechanism for the particle type grouping at intermediate values of pT for all harmonics.
Permanent Link: http://hdl.handle.net/11104/0269836