Probing jet hadrochemistry modification with measurements of $\mathbf{\pi}$, K, and p in jets and the underlying event in pp and Pb--Pb collisions at $\sqrt{s_{\rm{NN}}}$ = 5.02 TeV

TL;DR

This paper presents the first measurements of identified particle ratios within jets and the underlying event in pp and Pb--Pb collisions at 5.02 TeV, shedding light on jet-medium interactions and hadrochemistry modifications in quark-gluon plasma.

Contribution

It provides new experimental data on jet hadrochemistry in heavy-ion collisions, utilizing ALICE's particle identification capabilities to distinguish different particle species inside jets.

Findings

First measurements of $ ext{π}$, K, and p ratios in jets and underlying event.

Insights into soft particle production mechanisms in heavy-ion collisions.

Discrimination between different jet quenching models based on hadrochemistry.

Abstract

Measurements of jet substructure observables in heavy-ion (HI) collisions provide powerful constraints on the microscopic mechanisms of interactions between energetic partons and the quark--gluon plasma (QGP). Although there has been remarkable progress in measuring inclusive jet substructure, a complete understanding of identified particle production inside jets (jet hadrochemistry) and its modification in HI collisions remains elusive. Jet quenching models predict that the jet hadrochemical composition is modified in the QGP, arising from both jet-medium interactions and altered particle production in the jet wake. Measurements of jet hadrochemistry can help discriminate between proposed jet-medium interaction mechanisms. Enabled by the excellent particle identification (PID) capabilities of ALICE, we present the first measurements of $\pi$, K, and p ratios within jets and the underlying event as a function of particle transverse momentum in pp and Pb--Pb collisions at $\sqrt{s_{\rm{NN}}}$ = 5.02 TeV. These measurements provide insight into soft particle production mechanisms and helps distinguish various jet quenching effects.