Multiplicity dependence of identified particle production in proton-proton collisions with ALICE

Abstract

The study of identified particle production as a function of transverse momentum \(p_{\text{T}}\) and event multiplicity in proton-proton (pp) collisions at different center-of-mass energies \(\sqrt{s}\) is a key tool for understanding similarities and differences between small and large collisions systems. We report on the production of \(\pi^{\pm}\). \(K^{\pm}\). \(K^{0}_{S}\). \(p (\bar{p})\). \(\Lambda (\bar{\Lambda})\). \(\Xi^{\pm}\) and \(\Omega^{\pm}\) measured in pp collisions in a wide range of center-of-mass energies with ALICE. The multiplicity dependence of identified particle yields is presented for \(\sqrt{s} = \textrm{7}\) and \(13\) TeV and discussed in the context of the results obtained in proton-lead (p-Pb) and lead-lead (Pb-Pb) collisions, unveiling remarkable and intriguing similarities. The production rates of strange hadrons are observed to increase more than those of non-strange particles, showing an enhancement pattern with multiplicity which does not depend on the collision energy. Even if the multiplicity dependence of spectral shapes can be qualitatively described by commonly-used Monte Carlo (MC) event generators, the evolution of integrated yield ratios is poorly described by these models.