Speaker
Description
The data [1] on spectra of $K_S^0$ mesons measured by the STAR Collaboration in Au+Au collisions at various centralities characterized by different multiplicity densities of negative particles were analyzed in the $z$-scaling approach [2,3]. The transverse momentum distributions obtained in the BES-I program at RHIC were accumulated in seven centrality classes from the most central 0-5% to peripheral 60-80% collisions in the rapidity range $|y|<0.5$. These data and the earlier STAR data at $\sqrt {s_{NN}}=$ 62, 130 and 200 GeV allow us a detail study of the energy and centrality dependence of $K_S^0$-meson production in a wide range of $\sqrt {s_{NN}}=$ 7.7–200 GeV.
The scaling function $\psi(z)$ was constructed and the self-similarity of $K_S^0$-meson production was confirmed. It was found that the model parameter $c_{AuAu}$ interpreted as a specific heat of produced medium depends on collision energy. The scaling behavior is consistent with an abrupt decrease of $c_{AuAu}$ from the value of 0.16 at $\sqrt {s_{NN}}=$ 7.7 and 11.5 GeV to about 0.09 at the top RHIC energy. At $\sqrt {s_{NN}}=$39 GeV, a kink in the significant drop of this parameter is observed, as well as an indication of its flattening at higher $\sqrt {s_{NN}}$. The non-trivial dependence of $c_{AuAu}$ on the collision energy obtained from the $z$-scaling of $K_S^0$-meson production shows that the strange probe is much more sensitive to properties of nuclear medium than a non-identified negative hadron [3]. The irregularities in the behavior of the specific heat parameter cAuAu could indicate existence of a phase transition in nuclear matter.
- J. Adam et al. (STAR Collaboration), Phys. Rev. C 102, 034909 (2020).
- M. Tokarev et al., Phys. Part. Nucl. 51, 141 (2020).
- M. Tokarev, A. Kechechyan, I. Zborovský, Nucl. Phys. A 993, 121646 (2020).
| Section | 3. Intermediate and high energies, heavy ion collisions |
|---|---|
| The speaker is a student or young scientist | No |
