Topological studies of light-flavor hadron production in high multiplicity pp collisions with ALICE at the LHC

Abstract

Recent measurements in high-multiplicity pp and p-A collisions have revealed that these small collision systems exhibit collective-like behaviour, formerly thought to be achievable only in heavy-ion collisions. To understand the origins of these unexpected phenomena, event shape observables can be exploited, as they serve as a powerful tool to disentangle soft and hard contributions to particle production. Here, results on the production of light flavor hadrons for different classes of unweighted transverse spherocity ($S_{\rm 0}^{p_{\rm T}= 1}$) and relative transverse activity ($R_{\rm{T}}$) in high multiplicity pp collisions at $\sqrt{s}$ = 13 $\textrm{TeV}$ measured with the ALICE detector are presented. Hadron-to-pion ratios in different $S_{\rm 0}^{p_{\rm T}= 1}$ and $R_{\rm{T}}$ classes are also presented and compared with state-of-the-art QCD-inspired Monte Carlo event generators. The evolution of charged particle average transverse momentum ($\langle p_{\rm T}\rangle$) with multiplicity and $S_{\rm 0}^{p_{\rm T}= 1}$ is also discussed. In addition, the system size dependence of charged particle production in pp, p-Pb, and Pb-Pb collisions at $\sqrt{s_{\rm NN}}$= 5.02 TeV is presented. Finally, within the same approach, we present a search for jet quenching behavior in small collision systems.