Exploring nuclear structure with multiparticle azimuthal correlations at the LHC

Details of the nuclear structure of ¹²⁹Xe, 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 s _NN =5.44 TeV with the ALICE detector at the LHC. The results are compared with those from Pb–Pb collisions at s _NN =5.02 TeV for a baseline, given that the ²⁰⁸Pb 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 a₀=0.492 and a nuclear quadrupole deformation parameter of β₂=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.