Strangeness and charm at FAIR

Abstract

We study the properties of strange and charm mesons in hot and dense matter within a self-consistent coupled-channel approach for the experimental conditions of density and temperature expected for the CBM experiment at FAIR/GSI. The in-medium solution at finite temperature accounts for Pauli blocking effects, mean-field binding on all the baryons involved, and meson self-energies. In the strange sector, the $\bar K$ spectral function spreads over a wide range of energies, reflecting the melting of the $Λ(1405)$ resonance and the contribution of $(Λ,Σ,Σ^*)N^{-1}$ components at finite temperature. In the case of charm mesons, the dynamically-generated $Λ_c(2593)$ and $Σ_c(2880)$ 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 for energies close to the $D$ meson free-space mass that broadens with increasing matter density with an extended tail particularly towards lower energies. We also discuss the implications for the $D_{s0}(2317)$, $D_0(2400)$ and the predicted X(3700) resonances at FAIR energies.

5 pages, 4 figures, to appear in Proceedings of Quark Confinement and the Hadron Spectrum 8 Conference (Confinement8), Mainz (Germany), September 1-6, 2008