Testing the system size dependence of hydrodynamical expansion and thermal particle production with $\pi$, K, p, and $\phi$ in Xe-Xe and Pb-Pb collisions with ALICE

TL;DR

This paper investigates how system size influences hydrodynamical expansion and thermal particle production in heavy-ion collisions at the LHC, using data from Pb-Pb and Xe-Xe collisions to compare bulk particle production and collective effects.

Contribution

It provides new measurements of particle spectra and yields across different collision systems, and compares freeze-out parameters to understand system size dependence.

Findings

Bulk particle production varies with system size and multiplicity.

Collective effects evolve from small to large systems, consistent with hydrodynamic models.

Freeze-out parameters show systematic differences between collision types.

Abstract

We present new results on transverse momentum spectra, integrated yields, and mean transverse momenta of pions, kaons, and protons, as well as of $\phi$-mesons for various centrality classes measured in Pb-Pb and Xe-Xe collisions at the LHC. This unique set of data allows us to investigate bulk particle production for very different systems at similar multiplicities. The chemical and kinetic freeze-out parameters are extracted via statistical-thermal and combined blast-wave fits to the data in heavy-ion collisions and are compared to results obtained in pp and p-Pb collisions at similar multiplicities. The evolution of collective-like effects from pp and p-Pb collisions to Xe-Xe and Pb-Pb collisions is further investigated by detailed comparisons to predictions from models.