Mass shift and width broadening of rho-mesons produced in heavy ion collisions

The mass shift Delta m(rho) and width broadening Delta Gamma(rho) of rho-me sons produced in heavy ion collisions is estimated using general formulae w hich relate the in-medium mass shift of a particle to the real part of the forward scattering amplitude Ref(E) of this particle on constituents of the medium and Delta Gamma to the corresponding cross section. It is found tha t the mass increases by some tens of MeV but, more importantly, the width b ecomes large, increasing by several hundred Mev at beam energies of a few G eV.A and by twice that amount at beam energies of about a hundred GeV.A.