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 $D^{(\ast )}K$ and $\overline{D}{}^{(\ast )}\overline{K}$ $S$-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 $D^{(\ast )}$, $\overline{D}{}^{(\ast )}$, $K$, and $\overline{K}$ develop when embedded in a nuclear medium. Although particle-antiparticle [$D_{s0,s1}^{(\ast )}(2317,2460{)}^{+}$ versus $D_{s0,s1}^{(\ast )}(2317,2460{)}^{-}$] 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 $D^{(\ast )}K$/$\overline{D}{}^{(\ast )}\overline{K}$ molecular content, and discuss how this novel feature can be used to better determine/constrain the inner structure of these exotic states.

14 pages, 4 figures