The mass distributions of baryon resonances populated in near-central colli
sions of Au on Au and Ni on Ni are deduced by defolding the p(t) spectra of
charged pions by a method which does not depend on a specific resonance sh
ape. In addition the mass distributions of resonances are obtained from the
invariant masses of (p. pi(+/-)) pairs. With both methods the deduced mass
distributions are shifted by an average value of -60 MeV/c(2) relative to
the mass distribution of the free Delta(1232) resonance, the distributions
descent almost exponentially towards mass values of 2000 MeV/c(2). The obse
rved differences between (p, pi(-)) and (p, pi(+)) pairs indicate a contrib
ution of isospin I = 1/2 resonances. The attempt to consistently describe t
he deduced mass distributions and the reconstructed kinetic energy spectra
of the resonances leads to new insights about the freeze out conditions, i.
e. to rather low temperatures and large expansion velocities.