Probing identified and strange particle production using event-topology in pp collisions at √s = 13 TeV with ALICE

High-energy proton–proton (pp) collisions at the Large Hadron Collider provide a unique laboratory to investigate the dynamics of Quantum Chromodynamics (QCD) and the mechanisms responsible for hadron production. While pp collisions have traditionally served as a baseline for heavy-ion studies, recent measurements have revealed intriguing phenomena in high-multiplicity pp events, including strangeness enhancement and collective-like behaviour, which resemble features observed in larger collision systems. These observations have motivated detailed studies aimed at disentangling the interplay between soft and hard QCD processes and understanding the origin of such effects in small systems.

In this seminar, ALICE results on the transverse-spherocity dependence of light-flavor particle production, including pions, kaons, protons, φ mesons, K*0 resonances, K0S, Λ, and Ξ baryons, at midrapidity in high-multiplicity pp collisions at √s = 13 TeV will be presented. The transverse spherocity estimator is used to classify events according to their azimuthal topology, enabling a differential comparison between isotropic events dominated by multiple soft interactions and jet-like events dominated by hard scatterings. The seminar will discuss how event topology can be used as a powerful tool to investigate the connection between event hardness, particle production, and strangeness generation in high-multiplicity pp collisions. Comparisons with QCD-inspired Monte Carlo event generators will also be presented to assess how different model ingredients, such as multiparton interactions, string-density effects, thermal-like production mechanisms, and hadronization dynamics, describe the observed topology-dependent trends.