Exploring nuclear structure with multiparticle azimuthal correlations at the LHC

TL;DR

This study investigates the nuclear structure of $^{129}$Xe through anisotropic flow measurements in Xe--Xe collisions at the LHC, comparing results with models and Pb--Pb collisions to understand deformation and diffuseness effects.

Contribution

It provides the first systematic exploration of nuclear structure at TeV energies using anisotropic flow observables and benchmarks nuclear deformation parameters against experimental data.

Findings

Nuclear diffuseness parameter of 0.492 fits data better.

Quadrupole deformation parameter of 0.207 improves model agreement.

First systematic nuclear structure study at TeV energies.

Abstract

Details of the nuclear structure of $^{\rm 129}$Xe, such as the quadrupole deformation and the nuclear diffuseness, are studied by extensive measurements of anisotropic-flow-related observables in Xe--Xe collisions at a centre-of-mass energy per nucleon pair $\sqrt{s_{_{\mathrm{NN}}}}~=~5.44$ TeV with the ALICE detector at the LHC. The results are compared with those from Pb--Pb collisions at $\sqrt{s_{_{\mathrm{NN}}}}~=~5.02$ TeV for a baseline, given that the $^{\rm 208}$Pb nucleus exhibits a very weak deformation. Furthermore, comprehensive comparisons are performed with a state-of-the-art hybrid model using IP-Glasma+MUSIC+UrQMD. It is found that among various IP-Glasma+MUSIC+UrQMD calculations with different values of nuclear parameters, the one using a nuclear diffuseness parameter of $a_0=0.492$ and a nuclear quadrupole deformation parameter of $\beta_2=0.207$ provides a better description of the presented flow measurements. These studies represent the first systematic exploration of nuclear structure at TeV energies, utilizing a comprehensive set of anisotropic flow observables. The measurements serve as a critical experimental benchmark for rigorously testing the interplay between nuclear structure inputs and heavy-ion theoretical models.