Strange meson production at high density and temperature

TL;DR

This study investigates the behavior of strange mesons in dense nuclear matter using a coupled channels approach, accounting for medium effects, and proposes an experimental method to detect in-medium modifications of the $ar K^*$ meson.

Contribution

It introduces a comprehensive model combining chiral and hidden gauge formalisms to analyze strange mesons in dense matter, including spectral functions and experimental detection strategies.

Findings

Spectral functions of $K$, $ar K$, and $ar K^*$ in nuclear medium are computed.

In-medium modifications of strange mesons are characterized at finite density and temperature.

Proposes an experimental observable, the transparency ratio, to detect in-medium effects of $ar K^*$ mesons.

Abstract

The properties of strange mesons ($K$, $\bar K$ and $\bar K^*$) in dense matter are studied using a unitary approach in coupled channels for meson-baryon scattering. The kaon-nucleon interaction incorporates $s$- and $p$-wave contributions within a chiral model whereas the interaction of $\bar K^*$ with nucleons is obtained in the framework of the local hidden gauge formalism. The in-medium solution for the scattering amplitude accounts for Pauli blocking effects, mean-field binding on baryons, and meson self-energies. We obtain the $K$, $\bar K$ and $\bar K^*$ (off-shell) spectral functions in the nuclear medium and study their behaviour at finite density, temperature and momentum. We also analyze the energy weighted sum rules of the kaon propagator as a quality test of model calculations. We finally estimate the transparency ratio of the $\gamma A \to K^+ K^{*-} A^\prime$ reaction, which we propose as a feasible scenario at present facilities to detect in-medium modifications of the $\bar K^*$ meson.