11-16 July 2022
Europe/Moscow timezone
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A SPECIFIC HEAT OF NUCLEAR MEDIUM PROBED BY $K_S^0$ MESONS PRODUCED IN $Au+Au$ COLLISIONS AT RHIC

13 Jul 2022, 16:00
20m
НИИЯФ, ЮК, ауд. 3-13

НИИЯФ, ЮК, ауд. 3-13

Oral talk (15 min + 5 min questions) Intermediate and high energies, heavy ion collisions

Speaker

Prof. Mikhail Tokarev (Join Institute for Nuclear Research)

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.

  1. J. Adam et al. (STAR Collaboration), Phys. Rev. C 102, 034909 (2020).
  2. M. Tokarev et al., Phys. Part. Nucl. 51, 141 (2020).
  3. M. Tokarev, A. Kechechyan, I. Zborovský, Nucl. Phys. A 993, 121646 (2020).
The speaker is a student or young scientist No
Section 3. Intermediate and high energies, heavy ion collisions

Primary authors

Prof. Mikhail Tokarev (Join Institute for Nuclear Research) Dr Imrich Zborovsky (Nuclear Physics Institute, Academy of Sciences of the Czech Republic)

Presentation Materials