Studying light flavour hadrons produced in the collision of different nuclei at the LHC

TL;DR

This paper investigates how light flavor hadron production varies with collision geometry and multiplicity in heavy-ion collisions at the LHC, revealing that event hadrochemistry depends mainly on multiplicity rather than system or energy.

Contribution

First detailed comparison of particle production in Pb--Pb and Xe--Xe collisions at similar multiplicities, highlighting the dominance of multiplicity in event hadrochemistry.

Findings

Spectral shapes are mass-dependent in central collisions.

Particle yield ratios depend mainly on charged-particle multiplicity.

Event hadrochemistry is system- and energy-independent at LHC energies.

Abstract

The study of identified particle production as a function of event multiplicity is a key tool for understanding the similarities and differences among different colliding systems. Now for the first time, we can investigate how particle production is affected by the collision geometry in heavy-ion collisions at the LHC. In these proceedings, we report newly obtained ALICE results on charged and identified particle production in Pb--Pb and Xe--Xe collision at $\sqrt{s_{\rm NN}} = 5.02$ and $\sqrt{s_{\rm NN}} = 5.44$ TeV, respectively, as a function of transverse momentum ($p_{\rm T}$) and collision centrality. Particle spectra and ratios are compared between two different colliding systems at similar charged-particle multiplicity densities ($\langle{\rm d}N_{\rm ch}/{\rm d}\eta\rangle$), and different initial eccentricities. We find that in central collisions, spectral shapes of different particles are driven by their masses. The $p_{\rm T}$-integrated particle yield ratios follow the same trends with $\langle{\rm d}N_{\rm ch}/{\rm d}\eta\rangle$ as previously observed in other systems, further suggesting that at the LHC energies, event hadrochemistry is dominantly driven by the charged-particle multiplicity density and not the collision system, geometry or center-of-mass energy.}