$D$-mesons and charmonium states in hot pion matter

Abstract

We calculate the in-medium $D$ meson self-energies in a hot pion gas induced by resonance interactions with pions. The appropriate resonances in the {\it s},~ {\it p} and {\it d} waves of the $D$ meson-pion pair are represented by low lying scalar, vector and tensor $D^{\ast }$ mesons. At temperatures around 200 MeV the D-meson mass drops by $30\mathrm{MeV}$ and the scattering width grows up to $60\mathrm{MeV}$. Similar medium effects are found for the $D^{\ast }$ vector mesons. This opens and/or enhances the decay and/or dissociation channels of the charmonium states ${\Psi }^{\prime }$, ${\chi }_c$ and $J/\Psi$ to $D\bar{D},D^{\ast }\bar{D},D{\bar{D}}^{\ast },D^{\ast }{\bar{D}}^{\ast }$ pairs in pion matter.

Comments: 5 pages Revtex, 4 eps figures, final version accepted for publication in PRC