  Particle production yields measured in central Au-Au collision at RHIC are
obtained with free Fermi and Bose gases and also with a replacement of these
statistics by non-extensive statistics. For the latter calculation, a set of
different parameters was used with values of the Tsallis parameter $q$ chosen
between 1.01 and 1.25, with 1.16 generating the best agreement with
experimental data, an indication that non-extensive statistics may be one of
the underlying features in heavy ion-collisions.
