$D$ and $\bar{D}$ mesons in hot and dense matter

Abstract

The $D$ and $\bar{D}$ mesons are studied in hot dense matter within a self-consistent coupled-channel approach taking, as bare interaction, a broken SU(4) s-wave Tomozawa-Weinberg interaction supplemented by an attractive isoscalar-scalar term. The in-medium solution at finite temperature incorporates Pauli blocking effects, baryon mean-field bindings, and $\pi$ and open-charm meson self-energies. In the $DN$ sector, the ${\Lambda }_c$ and ${\Sigma }_c$ resonances remain close to their free-space position while acquiring a remarkable width. As a result, the $D$ meson spectral density shows a single pronounced peak close to the free mass that broadens with increasing density specially towards lower energies. The low-density theorem is not a good approximation for the repulsive $\bar{D}$ self-energy close to saturation density. We discuss the implications for the $J/\Psi$ suppression at CBM (FAIR).

Comments: 4 pages, 2 figures, to appear in the proceedings of the 11th International Conference on Meson-Nucleon Physics and the Structure of the Nucleon, Juelich, Germany, September 10-14, 2007