Identified particle production in pp collisions at $\sqrt{s}=$ 7 and 13 TeV measured with ALICE

TL;DR

This paper presents comprehensive measurements of identified particle production in proton-proton collisions at 7 and 13 TeV with ALICE, revealing multiplicity-dependent spectral shapes similar to larger systems, aiding the understanding of small vs. large collision systems.

Contribution

It provides the most extensive set of identified particle production results in pp collisions at the LHC, including new data at 13 TeV and detailed multiplicity dependence analysis.

Findings

Spectral shapes evolve with multiplicity similarly to larger systems.

Particle ratios show consistent evolution with multiplicity.

Results at 13 TeV extend the energy range of previous measurements.

Abstract

Proton-proton (pp) collisions have been used extensively as a reference for the study of interactions of larger colliding systems at the LHC. Recent measurements performed in high-multiplicity pp and proton-lead (p-Pb) collisions have shown features that are reminiscent of those observed in lead-lead (Pb-Pb) collisions. In this context, the study of identified particle spectra and yields as a function of multiplicity is a key tool for the understanding of similarities and differences between small and large systems. We report on the production of pions, kaons, protons, $K^{0}_{\rm S}$, $\Lambda$, $\Xi$, $\Omega$ and $K^{*0}$ as a function of multiplicity in pp collisions at $\sqrt{s}=$ 7 TeV measured with the ALICE experiment. The work presented here represents the most comprehensive set of results on identified particle production in pp collisions at the LHC. Spectral shapes, studied both for individual particles and via particle ratios as a function of $p_{\rm T}$, exhibit an evolution with charged particle multiplicity that is similar to the one observed in larger systems. In addition, results on the production of light flavour hadrons in pp collisions at $\sqrt{s}=$ 13 TeV, the highest centre-of-mass energy ever reached in the laboratory, are also presented and compared with previous, lower energy results.