Chemical freeze-out in Hawking-Unruh radiation and quark-hadron transition

TL;DR

This paper extends the analogy between hadron production and Hawking-Unruh radiation, providing a theoretical basis for freeze-out parameters in high-energy collisions and showing their consistency with experimental data.

Contribution

It introduces a black hole analogy to derive freeze-out parameters, connecting black hole physics with particle production in high-energy collisions.

Findings

Freeze-out temperature aligns with experimental hadronization data.

Entropy density condition $s/T^3\simeq7$ holds for low chemical potential.

Black hole analogy suggests minimal information loss during Hawking-Unruh radiation.

Abstract

The proposed analogy between hadron production in high-energy collisions and Hawking-Unruh radiation process in the black holes shall be extended. This mechanism provides a theoretical basis for the freeze-out parameters, the temperature ($T$) and the baryon chemical potential ($\mu$), characterizing the final state of particle production. The results from charged black holes, in which the electric charge is related to $\mu$, are found comparable with the phenomenologically deduced parameters from the ratios of various particle species and the higher-order moments of net-proton multiplicity in thermal statistical models and Polyakov linear-sigma model. Furthermore, the resulting freeze-out condition $\langle E\rangle/\langle N\rangle\simeq 1~$GeV for average energy per particle is in good agreement with the hadronization process in the high-energy experiments. For the entropy density ($s$), the freeze-out condition $s/T^3\simeq7$ remains valid for $\mu\lesssim 0.3~$GeV. Then, due to the dependence of $T$ on $\mu$, the values of $s/T^3$ increase with increasing $\mu$. In accordance with this observation, we found that the entropy density remains constant with increasing $\mu$. Thus, we conclude that almost no information is going lost through Hawking-Unruh radiation from charged black holes. It is worthwhile to highlight that the freeze-out temperature from charged black holes is determined independent on both freeze-out conditions