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

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 $k_{\mathrm{T},\mathrm{g}}$ 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.

arXiv comment6 pages, 4 figures, contribution to the proceedings of the 11th International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions (Hard Probes 2023), Aschaffenburg (Germany), March 26-31, 2023. Submitted to PoS