High energy partons created in ultra-relativistic heavy-ion collisions are modified due to their interaction with the surrounding medium, a phenomenon known as jet quenching. The study of the modifications of these rare probes provides crucial information about the properties of the medium, such as its transport coefficients and the nature of the degrees of freedom that govern its dynamical evolution. This high temperature medium, known as the quark-gluon plasma (QGP), corresponds to a new state of matter that is surprisingly well described by hydrodynamic simulations of an expanding droplet of a strongly coupled liquid. The goal of this project is to improve the physics and modelling of jet quenching phenomena through which we will extract conclusions about the nature of the QGP. A crucial ingredient consists in an accurate description of the interplay between the jet and the plasma, which requires a coupled hydrodynamical evolution that takes into account the source term corresponding to the energy deposited by the jet. The features of the source term, such as the energy deposition rate or its spatial extent, will be computed via holographic techniques, which are suited for the non-perturbative regime corresponding to the dominant QGP energy scale. Complementarily, rare high momentum exchanges with the QGP can result in both medium induced emissions and elastic scatterings, processes potentially capable of resolving the individual quarks and gluons in the QGP governing the small distance dynamics of an asymptotically free theory such as QCD. These perturbative processes will be modelled through diagrammatic techniques , where multi-parton quantum interference effects will have to be included. These results, incorporated in Monte Carlo simulations, will allow to accurately address pressing fundamental questions in our field such as the presence of QGP in small systems, the effect of coherence in energy loss, and the origin of the hydrodynamic behaviour itself.

Pablos Alfonso Daniel – INFN TORINO
Dr. Daniel Pablos obtained his PhD in Physics in 2016 in the University of Barcelona. After two postdoctoral stays (McGill University, University of Bergen), he is now conducting his research at the INFN Torino Unit. He is a leading worldwide expert on the physics of ``jet quenching'', which deals with the modifications of high-energy jets (collimated sprays of hadrons) as they pass through the quark-gluon plasma - a new state of matter produced in ultrarelativistic heavy-ion collisions. His research has heavily contributed to the advance of the field and provided key insights towards innovative new directions, both in theory and phenomenology.