Exploring medium properties with hard transverse momentum splittings using groomed jet substructure measurements in Pb--Pb collisions with ALICE

TL;DR

This paper presents new measurements of groomed jet substructure in Pb-Pb collisions at 5.02 TeV, using innovative grooming techniques to probe the Quark-Gluon Plasma and compare with theoretical models.

Contribution

It introduces the first application of dynamical grooming in heavy-ion collisions and compares multiple grooming methods in different collision systems.

Findings

Evidence of large-angle scattering signatures in groomed jet substructure

Comparison of grooming techniques shows consistent results across methods

Model calculations provide insights into jet-medium interactions

Abstract

Jet substructure observables provide unique probes of the properties of the Quark-Gluon Plasma (QGP). In these proceedings we report new measurements of groomed jet substructure in central Pb-Pb collisions at $\sqrt{s_\mathrm{NN}}=5.02$ TeV. We present the first application of dynamical grooming in heavy-ion collisions to search for excess $k_{\mathrm{T,g}}$ emissions, which is a signature of large-angle scattering of jets off quasi-particles in the QGP. We present additional measurements employing both the soft drop and dynamical grooming algorithms in 0-10% central Pb-Pb, 30-50% semicentral Pb-Pb, and proton-proton (pp) collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV. Results from the various grooming methods and parameters are compared. Comparisons to model calculations are also presented. The techniques developed for this measurement are more broadly applicable to jet substructure, which we likewise discussed.