Event-shape dependence of symmetry plane correlations using the Gaussian estimator in Pb-Pb collisions at the LHC using a multiphase transport model

Abstract

The study of symmetry plane correlations (SPCs) can be useful in characterizing the direction of the anisotropic emission of produced particles in the final state. The study of SPCs provides an independent method to understand the transport properties of the system formed in heavy-ion collisions. Similar to anisotropic flow coefficients, which are largely influenced by the initial spatial anisotropy, SPCs also depend on the participant plane correlations measured using the participating nucleons of the collision overlap region. In this paper, SPCs are studied in Pb-Pb collisions at (Formula presented) ¼ 5.02 TeV using the event generator AMPT. In addition to their behavior with the changing centrality of the collision, their event shape dependence is studied for the first time, using the event shape classifier transverse spherocity. The Gaussian estimator is used to evaluate the correlations, and these are compared with the participant plane correlations defined in an analogous way to the symmetry plane correlations, and a qualitative match is found between them. These event-shape-differentiated symmetry plane correlations can be used to deduce the presence of higher-order anisotropies in the initial energy distribution, thus giving insight into the initial geometry of the colliding system, among other applications, like model development and model testing using Bayesian analyses. © 2025 American Physical Society