  We propose new way of heavy ion collisions experiment data analysis. We
analyze physical parameters of fireball created in RHIC experiment based on
Grand Canonical Distribution and different Lattice QCD data available at the
moment. Our results on chemical potential are in agreement with previous model
estimations and do not depend on Lattice setup. At same time, we found possible
T(V) states of fireball and estimated the most probable temperature and volume
of fireball as function of collision energy. We conclude that hadrom matter at
RHIC experiment is thermalized and described by Grand Canonical Distribution.
