Mid-rapidity charged hadron transverse spherocity in pp collisions simulated with Pythia

TL;DR

This paper investigates how event shape variables like transverse spherocity in proton-proton collisions, simulated with Pythia, can help disentangle collective effects and underlying physics at high multiplicities.

Contribution

It introduces a differential analysis of multiplicity and event shapes in Pythia simulations to better understand collective-like effects in high-energy pp collisions.

Findings

Event shape analysis reveals differences in particle production.

High multiplicity events show features similar to collective flow.

Differential studies improve understanding of underlying physics.

Abstract

The pp collisions have been studied for a long time, however, there are still some effects which are not completely understood, such as the long range angular correlations and the flow patterns in high multiplicity events, which were recently discovered at the LHC. In a recent work it was demonstrated that in Pythia 8, multi-parton interactions and color reconnection can give some of the observed effects similar to the collective flow well known from heavy-ion collisions. Now using the same model, a study based on mid-rapidity charged hadron transverse spherocity is presented. The main purpose of this work is to show that a differential study combining multiplicity and event shapes opens the possibility to understand better the features of data, specially at high multiplicity.