Particle Ratios within a statistically corrected hadron resonance gas model and EPOS event-generator at AGS, SPS, RHIC and LHC Energies

TL;DR

This study compares a quantum-mechanically correlated hadron resonance gas model with experimental data and simulations across various energies, highlighting its strengths and limitations in predicting particle ratios in high-energy collisions.

Contribution

The paper introduces an improved HRG model inspired by Beth-Uhlenbeck corrections and compares its predictions with experimental data and other models across multiple energies.

Findings

HRG model closely matches experimental data for certain particle ratios.

The model addresses the proton anomaly at RHIC and LHC energies.

Significant underestimation of ratios involving strange and unequal-mass hadron pairs.

Abstract

We further investigate the applicability of our previously suggested quantum-mechanically correlated statistical hadron gas model (HRG) to the ideal hadron resonance gas model (IHRG), which is inspired by a Beth-Uhlenbeck corrected form of the equation of state (EoS). We compute the ratios of several particle yields, both equal-mass pairs ($\bar{p} / p$, $K^-/ K^+$, $\pi^-/ \pi^+$, $\bar{\Lambda}/ \Lambda$, $\bar{\Sigma}/ \Sigma$, $\bar{\Omega}/ \Omega$) and unequal-mass pairs ($p/ \pi^+$, $k^+/ \pi^+$, $k^-/ \pi^-$, $\Lambda/ \pi^-$, $\bar{p}/ \pi^-$, $\Omega/\pi^-$) and investigate how these ratios change with the center-of-mass energy. Next, we present a comparative analysis of the outputs of our suggested HRG model and the IHRG model, Cosmic Ray Monte Carlo (CRMC) EPOS $1.99$ simulations, and experimental data from ALICE, SPS, AGS, and RHIC. When compared to the other models taken into consideration, our HRG model typically shows very close agreement with the experimental results. The proton anomaly reported at top RHIC and LHC energies may be addressed by our new HRG model, which notably exhibits a strong alignment with experimental data for $\bar{p}/ \pi^-$ and $p/ \pi^+$ ratios. However, both our HRG model and the IHRG model seem to significantly underestimate some experimental data for ratios involving hadron couples with uneven mass and (multi)strange content, such as $\Lambda/ \pi^-$ and $\Omega/ \pi^-$. This emphasizes the necessity of additional research to determine whether thermal hadron gas models are appropriate and stresses the significance of any necessary adjustments to improve their correctness.