Hadronic spectral functions in nuclear matter

We study the in-medium properties of mesons (pi, eta, rho) and baryon resonances in cold nuclear matter within a coupled-channel analysis. The meson self energies are generated by particle-hole excitations. Thus multi-peak spectra are obtained for the mesonic spectral functions. In turn this leads to medium-modifications of the baryon resonances. Special care is taken to respect the analyticity of the spectral functions and to take into account effects from short-range correlations both for positive and negative parity states. Our model produces sensible results for pion and A dynamics in nuclear matter. We find a strong interplay of the p meson and the D 13 (1520), which moves spectral strength of the p spectrum to smaller invariant masses and leads to a broadening of the baryon resonance. The optical potential for the eta meson resulting from our model is rather attractive whereas the in-medium properties modifications of the S-11 (1535) are found to be quite small. (C) 2004 Elsevier B.V. All rights reserved.