What lattice QCD spectral functions can tell us about heavy quarkonium in the QGP

TL;DR

This paper reviews recent progress in understanding heavy-quarkonium behavior in the quark-gluon plasma using lattice QCD spectral functions and Bayesian methods, highlighting new insights and limitations.

Contribution

It presents novel lattice QCD spectral function computations of heavy quarkonium in medium, combining effective field theories with Bayesian analysis to extract physical properties.

Findings

Spectral functions reveal in-medium modifications of heavy quarkonium

Bayesian unfolding enhances spectral function reconstruction

Limitations of current approaches are discussed

Abstract

The bound states of a heavy quark and antiquark ($c\bar{c}, b\bar{b}$) are ideal probes to explore the quark-gluon plasma created in relativistic heavy-ion collisions at the RHIC and LHC. Not only have they become experimentally accessible with high precision but also efficient tools, so called effective field theories (EFT) have been developed to treat them theoretically. Here we present recent progress in understanding the in-medium behavior of heavy-quarkonium with the help of EFT's combined with non-perturbative and first principles simulations in lattice QCD. In particular we discuss computations of heavy quarkonium spectral functions with the help of Bayesian unfolding methods and the physics we can extract from them. Limitations and the underlying assumptions of the used approaches are pointed out.