Lattice study of static quark-antiquark interactions in dense quark matter

TL;DR

This study uses lattice simulations to analyze static quark-antiquark interactions in dense two-color quark matter, revealing how screening length and potentials change with density and confirming strong correlations in the medium.

Contribution

It provides the first detailed lattice calculation of grand potentials and screening effects for static quark pairs in dense two-color quark matter.

Findings

Screening length decreases with increasing baryon density.

Color singlet potential follows a Debye screening pattern.

Two-color quark matter remains strongly correlated at high density.

Abstract

In this paper we study the interactions among a static quark-antiquark pair in the presence of dense two-color quark matter with lattice simulation. To this end we compute Polyakov line correlation functions and determine the renormalized color averaged, color singlet and color triplet grand potentials. The color singlet grand potential allows us to elucidate the number of quarks induced by a static quark antiquark source, as well as the internal energy of such a pair in dense quark matter. We furthermore determine the screening length, which in the confinement phase is synonymous with the string breaking distance. The screening length is a decreasing function of baryon density, due to the possibility to break the interquark string via a scalar diquark condensate at high density. We also study the large distance properties of the color singlet grand potential in a dense medium and find that it is well described by a simple Debye screening formula, parameterized by a Debye mass and an effective coupling constant. The latter is of order of unity, i.e. even at large density two-color quark matter is a strongly correlated system.