News from Lattice QCD on Heavy Quark Potentials and Spectral Functions of Heavy Quark States

TL;DR

This paper reviews recent lattice QCD results on the in-medium behavior of heavy quark states, showing that certain charmonium states survive in the quark-gluon plasma up to 1.5 times the critical temperature.

Contribution

It clarifies the relation between heavy quark free energies and potentials, and presents spectral function calculations indicating the persistence of specific heavy quark states in hot QCD matter.

Findings

Charmonium states J/psi and eta_c remain as well-defined resonances up to 1.5 T_c.

Heavy quark free energies are related to potentials used in quarkonium melting analysis.

Lattice calculations at finite baryon density are briefly discussed.

Abstract

We discuss recent lattice results on in-medium properties of hadrons and focus on thermal properties of heavy quark bound states. We will clarify the relation between heavy quark free energies and potentials used to analyze the melting of heavy quark bound states. Furthermore, we present calculations of meson spectral functions which indicate that the charmonium ground states, J/psi and eta_c, persist in the quark gluon plasma as well defined resonances with no significant change of their zero temperature masses at least up to T ~ 1.5 T_c. We also briefly comment on the current status of lattice calculations at non-vanishing baryon number density.