A gauge invariant Debye mass and the complex heavy-quark potential

TL;DR

This paper introduces a gauge-invariant definition of the Debye mass derived from the complex heavy-quark potential in lattice QCD, providing a new way to understand screening effects in a gluonic medium.

Contribution

The authors derive an analytic formula linking the complex potential to a gauge-invariant Debye mass, validated by lattice QCD data and consistent with HTL perturbation theory.

Findings

The gauge-invariant Debye mass can be extracted from lattice QCD potentials.

The derived formula accurately reproduces both real and imaginary parts of the potential.

Debye masses obtained are compatible with HTL perturbation theory predictions.

Abstract

Following the original idea of Debye, we define and extract a gauge-invariant screening mass from the complex static in-medium heavy-quark potential $V_{Q\bar{Q}}$, recently obtained from lattice QCD. To this end we derive a field theoretically motivated analytic formula that faithfully reproduces both the screened real- as well as the imaginary part of the lattice potential with a single temperature dependent fit parameter $m_D(T)$. Using values of the real part of $V_{Q\bar{Q}}$ in a gluonic medium, we obtain Debye masses compatible with predictions from HTL perturbation theory.