Nuclear medium effects on the $\bar K^*$ meson

TL;DR

This paper investigates how the properties of the $ar K^*$ meson change in dense nuclear matter using a coupled-channel approach, revealing significant broadening of its spectral function and proposing an experimental method to observe these effects.

Contribution

It provides a novel analysis of the $ar K^*$ meson in dense matter using the local hidden gauge formalism and suggests an experimental observable for detecting medium modifications.

Findings

$ar K^*$ develops a width up to five times larger in matter.

Spectral function broadening indicates strong medium effects.

Transparency ratio can experimentally reveal in-medium modifications.

Abstract

The $\bar K^*$ meson in dense matter is analyzed by means of a unitary approach in coupled channels based on the local hidden gauge formalism. The $\bar K^*$ self-energy and the corresponding $\bar K^*$ spectral function in the nuclear medium are obtained. We observe that the $\bar K^*$ develops a width in matter up to five times bigger than in free space. We also estimate the transparency ratio of the $\gamma A \to K^+ K^{*-} A^\prime$ reaction. This ratio is an excellent tool to detect experimentally modifications of the $\bar K^*$ meson in dense matter.