Measuring the system size dependence of the strangeness production with ALICE

Lund University Department of Physics, Division of Particle and Nuclear Physics, Lund, Sweden

^* e-mail: roman.nepeivoda@cern.ch

Published online: 27 January 2025

Abstract

The system size dependence of strangeness production in highenergy collisions was studied using Run 2 data from the ALICE experiment at the LHC. The analysis examines the ratios of strange hadron yields to pion yields as a function of mid-rapidity charged particle multiplicity ⟨dN_ch/dη)_|η|&0.5, offering insights into the mechanisms driving strangeness enhancement across different collision systems (pp, p–Pb and Pb–Pb). The yield ratios exhibit a continuous rising trend from low-multiplicity pp collisions at √s = 7 TeV to central Pb–Pb collisions at √s_NN = 5.02 TeV. Additionally, the evolution of the mean transverse momentum (⟨p_T⟩) for various strange hadrons (K_S⁰, Λ(Λ¯), Ω^±, Ξ^±) is analyzed, revealing that ⟨p_T⟩ does not connect smoothly between different collision systems, with harder spectra observed in high-multiplicity pp collisions compared to the peripheral Pb–Pb collisions. Finally, performa plots from LHC Run 3 are presented, showcasing the purity of Ξ⁻ and Ω⁻ invariant mass distributions and highlighting the enhanced detector capabilities in Run 3.