Charm hadrons above $T_c$

TL;DR

This paper analyzes lattice data to show that open charm meson and baryon-like excitations are prevalent above the QCD transition temperature, dominating charm thermodynamics at higher temperatures.

Contribution

It provides evidence for the existence of open charm hadron-like excitations above the crossover temperature, highlighting their role in QCD thermodynamics.

Findings

Open charm meson and baryon-like excitations exist above T_c.

Charm quarks dominate charm degrees of freedom only above 200 MeV.

These excitations are the main contributors to thermodynamics near the transition.

Abstract

From the analysis of the lattice data on fluctuations and correlations of charm we conclude that open charm meson and baryon-like excitations exist above the QCD crossover temperature, and in fact are the dominant degrees of freedom for thermodynamics in the vicinity of the transition. Charm quarks become the dominant charm degrees of freedom only for temperatures T>200 MeV.