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Elliptic flow and incomplete equilibration at RHIC

R. S. Bhalerao·J. -P. Blaizot·N. Borghini·J. -Y. Ollitrault
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Abstract

We argue that RHIC data, in particular those on the anisotropic flow coefficients v_2 and v_4, suggest that the matter produced in the early stages of nucleus-nucleus collisions is incompletely thermalized. We interpret the parameter (1/S)(dN/dy), where S is the transverse area of the collision zone and dN/dy the multiplicity density, as an indicator of the number of collisions per particle at the time when elliptic flow is established, and hence as a measure of the degree of equilibration. This number serves as a control parameter which can be varied experimentally by changing the system size, the centrality of the collision, or the beam energy. We provide predictions for Cu-Cu collisions at RHIC as well as for Pb-Pb collisions at the LHC.

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R. S. Bhalerao, J. -P. Blaizot, N. Borghini, J. -Y. Ollitrault. 2005-08-31. Elliptic flow and incomplete equilibration at RHIC. https://doi.org/10.1016/j.physletb.2005.08.131

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