Properties of the $D_{s0}^*(2317)^\pm$ in hot and dense nuclear matter

Abstract

We investigate the properties of the $D_{s0}^\ast(2317)^\pm$ in hot and dense nuclear matter using a coupled-channel molecular model built on next-to-leading-order heavy meson chiral perturbation theory. In-medium modifications to the $D_{s0}^\ast(2317)^+$ stem from changes to the $DK$ channel within the coupled $DK$-$D_s \eta$ system. As nuclear density increases, the $D_{s0}^\ast(2317)^+$ quasiparticle peak shifts toward lower energies and broadens, tracking the behavior of the $D$-meson spectral function. As for temperature effects, those are milder, with the thermal smearing of the Fermi surface and the melting of $\Sigma_c N^{-1}$ excitations in the $D$-meson spectral function shifting the $D_{s0}^\ast(2317)^+$ peak back toward its free-space mass while narrowing it. Conversely, the behavior of the $D_{s0}^\ast(2317)^-$ is governed by the $\bar D \bar K$ channel and its medium behavior is driven by the $\bar K$ spectral function. With increasing temperature, the $D_{s0}^\ast(2317)^-$ also approaches its free-space mass, but its width broadens before saturating at high temperatures. Incorporating explicit medium dependencies into the interaction kernel, driven by density and/or temperature variations in the pion decay constant, further shifts the $D_{s0}^\ast(2317)^+$ mass lower and narrows its width with temperature. As for $D_{s0}^\ast(2317)^-$, its mass also drops with temperature but its width increases. These contrasting medium behaviors offer a promising pathway to constrain the internal structure of these exotic states.