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arXiv · 0710.1158

Why the $a_1$ meson might be a difficult messenger for the restoration of chiral symmetry

Sascha Vogel·Marcus Bleicher
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Abstract

We perform a theoretical analysis of the $a_1$ resonance mass spectrum in ultra-relativistic heavy ion collisions within a hadron/string transport approach. Predictions for the $a_1$ yield and its mass distribution are given for the GSI-FAIR and the critRHIC energy regime. The potential of the $a_1$ meson as a signal for chiral symmetry restoration is explored. In view of the latest discussion, we investigate the decay channel $a_1 \to γπ$ in detail and find a strong bias towards low $a_1$ masses. This apparent mass shift of the $a_1$ if observed in the $γπ$ channel might render a possible mass shift due to chiral symmetry restoration very difficult to disentangle from the decay kinematics.

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Sascha Vogel, Marcus Bleicher. 2007-10-05. Why the $a_1$ meson might be a difficult messenger for the restoration of chiral symmetry. https://doi.org/10.1103/physrevc.78.064910

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