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Our research

Smashing together the heaviest nuclei at the largest possible energies, creates conditions where ordinary nuclear matter melts into its most fundamental constituents – the quarks and gluons. This new state of matter is called the quark-gluon plasma (QGP) since the fundamental color degrees of freedom of nuclear matter can move around. In addition to this large-scale dynamics, often more violent crashes of quarks and gluons in the incoming nuclei create high-energy jets that lead to showers of particles measured in the detector. 

At the heavy-ion theory group at UiB, we work with different aspects of heavy-ion collisions. In particular, we study how jets interact with the QGP. Jets can be thought of as a highly out-of-equilibrium probe that, given enough time, eventually will thermalize with the surrounding medium. In course of this thermalization process, a lot of interesting processes are taking place. One of the most spectacular features is the rapid degradation of energy and its dissipation to very large angles. This is often referred to as a turbulent process.

In realistic heavy-ion collisions, many jets are only partially thermalized but their interaction with the QGP has left its mark. Most importantly, the jets have lost energy and their internal structure has been modified. Our task is mainly to understand how the jet shower evolution, which is a crucial and well understood part in proton-proton collisions, interfaces with the processes induced by the presence of the QGP. This is not only complicated by the fact that the shower is a quantum mechanical process, but also because the medium is highly fluctuating and has an intricate microscopic structure and evolution.

We are using a wide set of tools to achieve our goals. On the theory side, from perturbative techniques in QCD, light-cone field theory and resummation techniques. On the numerical side, we are developing a state-of-the-art Monte Carlo parton shower for heavy-ion collisions.