2025/02/10 by C. W. Robertson, Y. Feng, Robertson, C. W. +3 · 1 citation
Chemistry · Physics and Astronomy · #Advanced NMR Techniques and Applications #Data Analysis #FOS: Physical sciences #Nuclear Experiment (nucl-ex) #Quantum Chromodynamics and Particle Interactions #Quantum many-body systems #Statistics and Probability (physics.data-an)
paper · pdf · doi:10.48550/arxiv.2502.06576
openalex publication_date 2025/02/10 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Measurements of global spin alignment of vector mesons in relativistic heavy-ion collisions can provide unique insights into spin-orbit interactions and vector meson dynamics in the Quark-Gluon Plasma (QGP) produced in those collisions. The global spin alignment is measured by the 00\rm th coefficient of the spin density matrix, ρ00, via the polar angle (θ*) of the decay-daughter momentum in the parent rest frame with respect to the direction of the orbital angular momentum of the collision. Such measurements are affected by the angular and momentum resolutions of the reconstructed tracks in the experiment. Such effects are nontrivial because of kinematic complications caused by the boost to the parent rest frame, and could be important given that the global spin alignment signal is weak. In this paper, we investigate the effects of experimental tracking resolutions on measurements of the ϕ(1020) meson ρ00. We study these effects for two methods of ρ00 measurements, the conventional method analyzing the ϕ-meson yield versus cos2 θ^* and the invariant mass (m\rm inv) method utilizing ⟨cos2θ^*⟩ versus m\rm inv. Using typical resolution values from experiments, we find that the effect of track resolution on ρ00 is small, well within typical measurement uncertainties.