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In-medium effects on the $K^-/K^+$ ratio at GSI

L. Tolos·A. Polls·A. Ramos·J. Schaffner-Bielich
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Abstract

The in-medium modifications on the $K^-/K^+$ ratio produced at GSI are studied. Particular attention is paid to the properties of antikaons, which determine the chemical potential and temperature at freeze-out conditions. Different approaches have been considered: non-interacting $K^-$, on-shell self-energy and single-particle spectral density. We observe that the full off-shell approach reproduces the "broad-band equilibration" advocated by Brown being the spectral density crucial to explain an enhanced $K^-/K^+$ ratio.

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L. Tolos, A. Polls, A. Ramos, J. Schaffner-Bielich. 2005-01-26. In-medium effects on the $K^-/K^+$ ratio at GSI. https://doi.org/10.1016/j.nuclphysa.2005.01.026

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