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arXiv · hep-ph/0211119

Matter-induced modification of resonances at RHIC freezeout

Abstract

We discuss the physical effects causing a modification of resonance masses, widths and even shapes in a dilute hadronic gas at late stages of heavy ion collisions. We quantify the conditions at which resonances are produced at RHIC, and found that it happens at $T\approx 120 MeV$. Although in the pp case the ``kinematic'' effects like thermal weighting of the states is sufficient, in AA we see a clear effect of dynamical interaction with matter, both due to a variety of s-channel resonances and due to t-channel scalar exchanges. The particular quantity we focus mostly on is the $ρ$ meson mass, for which these dynamical effects lead to about -50 MeV shift, on top of about -20 MeV of a thermal effect: both agree well with preliminary data from STAR experiment at RHIC. We also predict a complete change of shape of $f_0(600)$ resonance, even by thermal effects alone.

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BibTeXRIS

E. V. Shuryak, G. E. Brown. 2002-11-18. Matter-induced modification of resonances at RHIC freezeout. https://doi.org/10.1016/s0375-9474(03)00672-9

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