Anisotropic flow of identified particles in Pb–Pb collisions at √sNN = 2.76 TeV measured with ALICE at the LHC
1 Museo storico della fisica e centro studi e ricerche “E. Fermi”
2 INFN, Bologna ( Italy )
Published online: 24 March 2015
The anisotropic flow (υn) of identified particles is an important observable to probe the freeze-out properties, the parton energy loss and the transport coefficients of the system created in heavy-ion collisions. We report on the anisotropic flow measurements for a number of identified particles such as charged pions, kaons and (anti-)protons, as well as K0s, Λ(Λ̄), ϕ, Ξ−(Ξ̅+), and Ω−(Ω̅+). The measurements are performed in the rapidity range |y| < 0.5, over a wide range of transverse momenta, 0.2 < pT < 6 GeV/c, for Pb–Pb collisions at √sNN = 2.76 TeV recorded by ALICE at the LHC. We will present the mass ordering as a function of transverse momentum for several collision centralities compared with results allower energies. While in the low pT region hydrodynamical computations describe the experimental data points fairly well, at intermediate momenta the quark number (nq) scaling indicates that it holds at an approximate level of 20–30%. Finally, focusing on the low momentum region ALICE has recently observed a similar mass ordering behaviour of υ2 in p–Pb systems. We will present this intriguing result which may be connected to a collective effect similar to that observed in Pb–Pb collisions.
© Owned by the authors, published by EDP Sciences, 2015
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