${\bar{K}}^{\ast }$ meson in dense matter

We study the properties of ${\bar{K}}^{\ast }$ mesons in nuclear matter using a unitary approach in coupled channels within the framework of the local hidden gauge formalism and incorporating the $\bar{K}\pi$ decay channel in matter. The in-medium ${\bar{K}}^{\ast }N$ interaction accounts for Pauli blocking effects and incorporates the ${\bar{K}}^{\ast }$ self-energy in a self-consistent manner. We also obtain the ${\bar{K}}^{\ast }$ (off-shell) spectral function and analyze its behaviour at finite density and momentum. At normal nuclear matter density, the $\bar K^$mesonfeelsamoderatelyattractivepotentialwhilethe$\bar K^$ width becomes five times larger than in free space. We estimate the transparency ratio of the $\gamma A\to K^{+}{K}^{\ast -}{A}^{\mathrm{\prime }}$ reaction, which we propose as a feasible scenario at present facilities to detect the changes of the properties of the ${\bar{K}}^{\ast }$ meson in the nuclear medium.