Charm mesons at FAIR

Abstract

The in-medium properties of charm mesons ($D$ and $\bar D$) in a hot and dense matter are studied. A self-consistent coupled-channel approach is driven by a broken SU(4) s-wave Tomozawa-Weinberg interaction supplemented by an attractive isoscalar-scalar term. As medium effects, we include Pauli blocking, baryon mean-field bindings, and $π$ and open-charm meson self-energies. The dynamically generated $\tildeΛ_c$ and $\tildeΣ_c$ resonances in the $DN$ sector remain close to their free space position but acquire large widths. The resultant $D$ meson spectral function, which shows a single pronounced quasiparticle peak close to the free mass that broadens with increasing density, also has a long low energy tail associated with smeared $\tildeΛ_c N^{-1}$, $\tildeΣ_c N^{-1}$ configurations. The low-density approximation for the $\bar D N$ is questionable already at subsaturation densities. We touch upon the implication of our study for $J/Ψ$ suppression at FAIR.

4 pages, 3 figures, contribution to the proceedings of Chiral07, RCNP, Osaka, Japan, November 13-16, 2007