Comparing effective temperatures in standard, Tsallis, and q-dual statistics from transverse momentum spectra of identified light charged hadrons produced in gold--gold collisions at RHIC energies

Abstract

This study investigates the transverse momentum ($p_T$) spectra of identified light charged hadrons produced in gold--gold (Au+Au) collisions across various centrality classes at center-of-mass energies per nucleon pair, $\sqrt{s_{NN}}$, ranging from 7.7 to 200 GeV, as measured by the STAR Collaboration at the Relativistic Heavy Ion Collider (RHIC). The analysis employs standard (Bose-Einstein/Fermi-Dirac), Tsallis, and q-dual statistics to fit the same $p_T$ spectra and derive distinct effective temperatures: $T_{\text{Standard}}$, $T_{\text{Tsallis}}$, and $T_{\text{q-dual}}$. In most instances, there exists an approximately linear relationship or positive correlation between $T_{\text{Tsallis}}$ and $T_{\text{Standard}}$, as well as between $T_{\text{q-dual}}$ and $T_{\text{Standard}}$, when considering $T_{\text{Standard}}$ as a baseline. However, while both $T_{\text{Tsallis}}$ and $T_{\text{q-dual}}$ increase from semi-central to central Au+Au collisions at 62.4 GeV and 200 GeV, where QGP is expected, changes in $T_{\text{Standard}}$ occur more gradually. This work suggests that $T_{\text{Standard}}$ is better suited for characterizing phase transitions between hadronic matter and QGP compared to $T_{\text{Tsallis}}$ or $T_{\text{q-dual}}$, primarily due to the considerations related to entropy index in the Tsallis and q-dual statistics.