# QM 2022

Apr 4 – 10, 2022
Auditorium Maximum UJ
Europe/Warsaw timezone
Proceedings submission deadline extended to August 15, 2022

## Dynamically groomed jet radius in heavy-ion collisions

Apr 6, 2022, 7:22 PM
4m
Poster Jets, high-pT hadrons, and medium response

### Speaker

Dr Paul Caucal (Brookhaven National Laboratory)

### Description

Jet substructure is a powerful tool to probe the perturbative regime of jet evolution in proton-proton and heavy-ion collisions. Over the past few years, a wide variety of substructure observables have been proposed in order to understand specific aspects of jet dynamics in a quark-gluon plasma (QGP).

In this talk, based on [1], we will explore the ability of such an observable, called Dynamical Grooming [2], to pin down the properties of the QGP. In particular, we will present the computation via analytic resummation techniques and Monte-Carlo simulations, of the opening angle $\theta_g$ of the hardest splitting in the jet as defined by Dynamical Grooming. This calculation, grounded in perturbative QCD, accounts for the factorization in time between vacuum-like and medium-induced processes in the double logarithmic approximation.
Our main result is that the dominating scale in the $\theta_g$-distribution is the decoherence angle $\theta_c$ which characterizes the resolution power of the medium to propagating color probes, which makes this observable particularly interesting to measure $\theta_c$ experimentally. To that aim, we will highlight a suitable combination of the Dynamical Grooming condition and the jet radius that leads to a pQCD dominated observable with a very small sensitivity to medium response.

Refs:
[1] P. Caucal, A. Soto-Ontoso and A. Takacs, arXiv:2111.14768
[2] Y. Mehtar-Tani, A. Soto-Ontoso and K. Tywoniuk, arXiv:1911.00375

### Primary authors

Adam Takacs (University of Bergen) Alba Soto Ontoso (IPhT) Dr Paul Caucal (Brookhaven National Laboratory)