PHENIX highlights: Recent results from PHENIX

¹ Department of Mathematical and Physical Sciences, Nara Women’s University
² RIKEN Nishina Center

^* e-mail: maya@cc.nara-wu.ac.jp

Published online: 27 January 2025

Abstract

The Relativistic Heavy Ion Collider (RHIC) PHENIX experiment has provided new insights into the behavior of quark-gluon plasma (QGP) under extreme conditions. While PHENIX concluded data collection in 2016, the collaboration remains actively engaged in analyzing the rich dataset yielding the following three important results recently. (1) Heavy flavor (HF) with charm and bottom quark separation indicates a clear mass dependence observed in central collisions. Additionally, forward rapidity J/ψ and v₂ measurements show a result consistent with zero, in contrast to LHC findings. (2) Precise direct photon yields obtained via large statistical datasets, spanning a wide range of transverse momentum (p_T) and centrality bins have the scaling behavior across various large systems, and non-prompt direct photon results reveal temperature (T_eff) dependence on p_T. (3) Charged hadron production was examined in collision systems of varying sizes, revealing that R_AA is primarily dependent on the overlap volume (N_part). Moreover, R_dAu obtained by experimental N_coll suggests the clear yield suppression in central collisions.