Impact of a thermal medium on $D$ mesons and their chiral partners

Abstract We study D and D s mesons at finite temperature using an effective field theory based on chiral and heavy-quark spin-flavor symmetries within the imaginary-time formalism. Interactions with the light degrees of freedom are unitarized via a Bethe-Salpeter approach, and the D and D s self-energies are calculated self-consistently. We generate dynamically the D 0 ⁎ ( 2300 ) and D s ( 2317 ) states, and study their possible identification as the chiral partners of the D and D s ground states, respectively. We show the evolution of their masses and decay widths as functions of temperature, and provide an analysis of the chiral-symmetry restoration in the heavy-flavor sector below the transition temperature. In particular, we analyse the very special case of the D-meson, for which the chiral partner is associated to the double-pole structure of the D 0 ⁎ ( 2300 ) .