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arXiv · 0910.0392

Why is $v_4/(v_2)^2$ larger than predicted by hydrodynamics?

Clément Gombeaud·Jean-Yves Ollitrault
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Abstract

The second and fourth Fourier harmonics of the azimuthal distribution of particles, $v_2$ and $v_4$, have been mesured in Au-Au collisions at the Relativistic Heavy Ion Collider (RHIC). The ratio $v_4/(v_2)^2$ is significantly larger than predicted by hydrodynamics. Effects of partial thermalization are estimated on the basis of a transport calculation, and are shown to increase the ratio by a small amount. We argue that the large value of $v_4/(v_2)^2$ seen experimentally is mostly due to elliptic flow fluctuations. However, the standard model of eccentricity fluctuations is unable to explain the large magnitude of $v_4/(v_2)^2$ in central collisions.

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Clément Gombeaud, Jean-Yves Ollitrault. 2009-10-02. Why is $v_4/(v_2)^2$ larger than predicted by hydrodynamics?. https://doi.org/10.1016/j.nuclphysa.2010.01.002

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