  The mass shift and width broadening of rho-mesons produced in heavy ion
collisions is estimated using general formulae which relate the in-medium mass
shift of a particle to the real part of the forward scattering amplitude of
this particle on constituents of the medium and the width broadening to the
corresponding cross section. It is found that the mass increases by some tens
of MeV but, more importantly, the width becomes large, increasing by several
hundred MeV at beam energies of a few GeV per nucleon and by twice that amount
at beam energies of about a hundred GeV per nucleon.

Nuclear Theory;High Energy Physics - Phenomenology