New Insights into Global Spin Alignment of Vector Mesons Using Relativistic Heavy-Ion Collisions from STAR

2023/12/25 by B. Xi, Xi, Baoshan
Economics, Econometrics and Finance · Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High-Energy Particle Collisions Research #Nuclear Experiment (nucl-ex) #Quantum Chromodynamics and Particle Interactions #Spatial and Panel Data Analysis

paper · pdf · doi:10.48550/arxiv.2312.15756

openalex publication_date 2023/12/25 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

In these proceedings, we present new measurements from STAR of the global spin alignment(ρ₀₀) of ϕ mesons in Au+Au collisions at √s_NN = 19.6, 14.6 GeV using BES-II data and of J/ψ mesons in isobar collisions ₄₄⁹⁶ Ru+ ₄₄⁹⁶ Ru and ₄₀⁹⁶ Zr+ ₄₀⁹⁶ Zr at √s_NN = 200 GeV. The energy-dependent spin alignment for ϕ mesons from BES-II data is consistent with that published from BES-I and showcases a significant improvement in precision. We performed a new measurement assessing the rapidity dependence of ϕ meson ρ₀₀, and our findings are consistent with theoretical predictions. The global spin alignment of J/ψ mesons with respect to first order event plane aligns with a value of 1/3 within the statistical error. Additionally, we discuss the procedure of measuring the global spin alignment of ρ⁰ mesons at RHIC and provide the projection for errors.

Related

• Measurement of global spin alignment of vector mesons at RHIC
• Momentum dependence of ϕ meson's spin alignment
• Practical Considerations for Measuring Global Spin Density Matrix Elements of Vector Mesons in Heavy-Ion Collisions
• Impact of Tracking Resolutions on ϕ-Meson Spin Alignment Measurement
• First measurement of D^*+ vector spin alignment in Pb-Pb collisions at \mathbf√s_{\rm NN} = 5.02 TeV