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arXiv · 0907.1392

Effects of partial thermalization on HBT interferometry

Clément Gombeaud·Tuomas Lappi·Jean-Yves Ollitrault
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Abstract

Hydrodynamical models have generally failed to describe interferometry radii measured at RHIC. In order to investigate this ``HBT puzzle'', we carry out a systematic study of HBT radii in ultrarelativistic heavy-ion collisions within a two-dimensional transport model. We compute the transverse radii $R_o$ and $R_s$ as functions of $p_t$ for various values of the Knudsen number, which measures the degree of thermalization in the system. For realistic values of the Knudsen number estimated from $v_2$ data, we obtain $R_o/R_s \simeq 1.2$, much closer to data than standard hydrodynamical results. Femtoscopic observables vary little with the degree of thermalization. Azimuthal oscillations of the radii in non central collisions do not provide a good probe of thermalization.

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Clément Gombeaud, Tuomas Lappi, Jean-Yves Ollitrault. 2009-09-25. Effects of partial thermalization on HBT interferometry. https://doi.org/10.1016/j.nuclphysa.2009.10.075

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