Jets as a probe of the quark-gluon plasma

Abstract

The suppression and modification of high-energy objects, like jets, in heavy-ion collisions provide an important window to access the degrees of freedom of the quark-gluon plasma on different length scales. Despite increasingly precise and differential measurements of the properties of jets in heavy-ion collisions, however, it has remained challenging to use jets to make unambiguous and model-independent statements about the quark-gluon plasma. Here I will give a personal take on some origins of these challenges, including the difficulty of modelling and biases from jet selection that obfuscate the direct interpretation of jet modification measurements. I will discuss a few model studies that have helped to disentangle the source of non-intuitive effects in measurements, and finally highlight data-driven approaches as an interesting opportunity toward studying the quark-gluon plasma in a model-independent way using jets.

Studying the impact of the nucleon size in relativistic heavy-ion collisions

“…At this point, the energy density across all of the system is much larger than 500 MeV/fm 3 , the typical energy density inside hadrons [34]. Most of the initial interactions between partons are soft, but rare scatterings with very large momentum transfer also occur, leading to the formation of jets [35,36]. In this initial moments after the collision, the system expands violently, close to the speed of light.…”