Specific Heat of Nuclear Medium Probed by Mesons Produced in Collisions at RHIC

The energy and centrality dependence of -meson spectra measured by the STAR Collaboration at RHIC in collisions over a wide range of GeV was studied in the -scaling approach. The scaling function was constructed and the self-similarity of -meson production was confirmed. This observation is consistent with an abrupt decrease of the model parameter from the value of 0.16 at and 11.5 GeV to about 0.09 at the top RHIC energy. The scaling parameter is interpreted as a specific heat of the produced medium. The non-trivial dependence of on the collision energy shows that meson is much more sensitive to properties of nuclear medium than a non-identified negative hadron. The irregularities in the behavior of the specific heat parameter are considered as a possible indication of phase transition in nuclear matter.