2025/07/31 by M. Svoboda, Svoboda, Michal
Physics and Astronomy · #FOS: Physical sciences #Gamma-ray bursts and supernovae #High Energy Physics - Experiment (hep-ex) #Magnetic confinement fusion research #Nuclear Experiment (nucl-ex) #Solar and Space Plasma Dynamics
paper · pdf · doi:10.48550/arxiv.2507.23471
openalex publication_date 2025/07/31 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Jets serve as an important tool to probe QCD both in the vacuum and in the hot and dense medium. The STAR experiment at RHIC plays a key role in studying QCD phenomena across different collision systems (p+p, p+A, A+A), offering access to a kinematic regime that complements that of the LHC. Building on recent jet and event activity studies at STAR, we present recent measurements on charged-particle jets at √sNN~=~200 GeV. In p+Au collisions, we explore event activity (EA) measured in the Au-going direction and its correlation with particle production at mid-rapidity. While soft particle production increases with EA, high-pT jets are found to be inversely related to EA. Ratios of pT imbalance and azimuthal dijet separation between high- and low-EA events show no significant differences, suggesting no strong evidence of jet quenching in high-EA p+Au collisions. In Au+Au collisions, we report semi-inclusive measurements of jets recoiling from γ and π0 triggers, using mixed-event techniques to subtract background and study jet suppression, intra-jet broadening, and acoplanarity. Additionally, we present inclusive charged-particle jet spectra corrected for background fluctuations, extending the kinematic reach of previous measurements. These results provide crucial insight into the modification of jets in the medium and contribute to a deeper understanding of QCD in heavy-ion collisions.