  Recent measurements of the pi^+pi^- invariant mass distribution at RHIC show
a shifted peak for the rho meson in 100A GeV in peripheral Au + Au and even in
p + p collisions. A recent theoretical study based on a picture of in-medium
production rates of pions, showed that a large shift could result from a
combination of the Boltzmann factor and the collisional broadening of the rho.
Here we argue that the two-pion density of states is the appropriate quantity
if one assumes a sudden break-up of the system. Methods for calculating the
density of states which include Bose effects are derived. The resulting
invariant mass distributions are significantly enhanced at lower masses and the
rho peak is shifted downward by ~ 35 MeV.
