Event-shape studies of strangeness production in √S = 13 TeV proton–proton collisions with ALICE

¹ Lund University, Sweden

^* e-mail: adrian.nassirpour@hep.lu.se

Published online: 1 February 2022

Abstract

The ALICE Collaboration has observed that the relative fraction of strange hadrons grows strongly with multiplicity in small collision systems at LHC energies, in particular for multi-strange baryons. The origin of this effect is still under debate, and models need significant final-state interactions to accommodate the new ALICE results, requiring new tools to discriminate experimentally between the various phenomenological ideas.

In these proceedings we present a multi-differential study of identified particle spectra with respect to the event multiplicity and two different event shape observables, the unweighted transverse spherocity S_O^pT=1, and the self-normalized, transverse charged particle density, R_T, which allows us to explore particle production associated with hard and soft QCD processes. ALICE has measured π, K, ϕ, and Ξ production at mid-rapidity (|η| < 0.8) as a function of S_O^pT=1 and R_T in pp collisions at √S = 13 TeV. This work reports on how these multi-differential measurements compare with predictions from PYTHIA and EPOSLHC.