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arXiv · 1105.2647

Energy loss in a fluctuating hydrodynamical background

Thorsten Renk·Hannu Holopainen·Jussi Auvinen·Kari J. Eskola
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Abstract

Recently it has become apparent that event-by-event fluctuations in the initial state of hydrodynamical modelling of ultrarelativistic heavy-ion collisions are crucial in order to understand the full centrality dependence of the elliptic flow coefficient v_2. In particular, in central collisions the density fluctuations play a major role in generating the spatial eccentricity in the initial state. This raises the question to what degree high P_T physics, in particular leading-parton energy loss, which takes place in the background of an evolving medium, is sensitive to the presence of the event-by-event density fluctuations in the background. In this work, we report results for the effects of fluctuations on the nuclear modification factor R_AA in both central and noncentral sqrt(s_NN) = 200 GeV Au+Au collisions at RHIC. Two different types of energy-loss models, a radiative and an elastic, are considered. In particular, we study the dependence of the results on the assumed spatial size of the density fluctuations, and discuss the angular modulation of R_AA with respect to the event plane.

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Thorsten Renk, Hannu Holopainen, Jussi Auvinen, Kari J. Eskola. 2011-05-13. Energy loss in a fluctuating hydrodynamical background. https://doi.org/10.1103/physrevc.85.044915

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