Charge-conjugation asymmetry and molecular content: the $D_{s0}^\ast(2317)^\pm$ in matter

Abstract

We analyze the modifications that a dense nuclear medium induces in the $D_{s0}^\ast(2317)^\pm$ and $D_{s1}(2460)^\pm$. In the vacuum, we consider them as isoscalar $D^{(*)}K$ and $\overline{D}{}^{(*)}\overline{K}$ $S$-wave bound states, which are dynamically generated from effective interactions that lead to different Weinberg compositeness scenarios. Matter effects are incorporated through the two-meson loop functions, taking into account the self energies that the $D^{(*)}$, $\overline{D}{}^{(*)}$, $K$, and $\overline{K}$ develop when embedded in a nuclear medium. Although particle-antiparticle [$D^{(\ast)}_{s0,s1}(2317,2460)^+$ versus $D^{(\ast)}_{s0,s1}(2317,2460)^-$] lineshapes are the same in vacuum, we find extremely different density patterns in matter. This charge-conjugation asymmetry mainly stems from the very different kaon and antikaon interaction with the nucleons of the dense medium. We show that the in-medium lineshapes found for these resonances strongly depend on their $D^{(*)}K$/$\overline{D}{}^{(*)}\overline{K}$ molecular content, and discuss how this novel feature can be used to better determine/constrain the inner structure of these exotic states.