Specific Heat of Nuclear Medium Probed by K-S(0) Mesons Produced in Au plus Au Collisions at RHIC

The energy and centrality dependence of K-S(0)-meson spectra measured by the STAR Collaboration at RHIC in Au + Au collisions over a wide range of v root s(NN) = 7.7- 200 GeV was studied in the z-scaling approach. The scaling function Psi(z) was constructed and the self-similarity of K-S(0) -meson production was confirmed. This observation is consistent with an abrupt decrease of the model parameter cAuAu from the value of 0.16 at root s(NN) = 7.7 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 cAuAu on the collision energy shows that K-S(0) 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 cAuAu are considered as a possible indication of phase transition in nuclear matter.