Dynamically groomed jet radius in heavy-ion collisions

Abstract

We explore the ability of a recently proposed jet substructure technique, Dynamical Grooming, to pin down the properties of the Quark-Gluon Plasma formed in ultra-relativistic heavy-ion collisions.In particular, we compute, both analytically and via Monte-Carlo simulations, the opening angle θg of the hardest splitting in the jet as defined by Dynamical Grooming. Our calculation, grounded in perturbative QCD, accounts for the factorization in time between vacuum-like and medium-induced processes in the double logarithmic approximation. We observe that the dominating scale in the θgdistribution is the decoherence angle θc which characterises the resolution power of the medium to propagating color probes. This feature also persists in strong coupling models for jet quenching. We further propose for potential experimental measurements a suitable combination of the Dynamical Grooming condition and the jet radius that leads to a pQCD dominated observable with a very small sensitivity (≤ 10%) to medium response. I. JET SUBSTRUCTURE IN HEAVY-ION COLLISIONS

Jet broadening in dense inhomogeneous matter

“…Particularly, it would be interesting to explore to what extent the jet substructure grooming/tagging techniques, see e.g. [78][79][80][81][82][83] could be used to look for matter inhomogeneity effects on the angular spectrum of the hardest substructures within the jet. Such new observables would provide a window to further probe the medium properties locally along the ideas of jet tomography.…”