From Complex to Stochastic Potential: Heavy Quarkonia in the Quark-Gluon Plasma

TL;DR

This paper reviews recent progress in defining a complex, stochastic potential for heavy quarkonium in quark-gluon plasma from first principles QCD, connecting fundamental physics to phenomenological predictions.

Contribution

It introduces a first-principles approach to derive a complex stochastic potential for heavy quarkonium at finite temperature from lattice QCD simulations.

Findings

Complex potential extracted from lattice QCD

Interpretation of imaginary part as spatial decoherence

Discussion of potential improvements

Abstract

The in-medium physics of heavy quarkonium is an ideal proving ground for our ability to connect knowledge about the fundamental laws of physics to phenomenological predictions. One possible route to take is to attempt a description of heavy quark bound states at finite temperature through a Schroedinger equation with an instantaneous potential. Here we review recent progress in devising a comprehensive approach to define such a potential from first principles QCD and extract its, in general complex, values from non-perturbative lattice QCD simulations. Based on the theory of open quantum systems we will show how to interpret the role of the imaginary part in terms of spatial decoherence by introducing the concept of a stochastic potential. Shortcomings as well as possible paths for improvement are discussed.