QCD color interactions between two quarks

TL;DR

This study investigates the color interactions between two static heavy quarks in QCD using lattice simulations, revealing different potential behaviors across various color channels and their dependence on quark separation.

Contribution

It provides the first detailed lattice calculation of octet and symmetric $qq$ potentials, including their distance dependence and string tension ratios, expanding understanding of quark interactions.

Findings

Antisymmetric $qq$ channel exhibits linearly rising potential at large distances.

Octet $qar{q}$ and symmetric $qq$ potentials are repulsive at short distances and linearly rising at large distances.

String tension ratios align with Casimir scaling predictions.

Abstract

We study the QCD color interactions between static two heavy quarks at zero temperature in a quenched SU(3) lattice gauge simulation: in addition to the standard singlet $q\bar{q}$ potentials, we calculate octet $q\bar{q}$ potentials, symmetric and antisymmetric $qq$ potentials. It is shown that the antisymmetric $qq$ channel behaves as a linearly rising potential at large quark separations. We further find that the $q\bar{q}$ octet and $qq$ symmetric channels have the complex dependence on the distance; at short distances they are repulsive forces, while at large distances, they show linearly rising feature. Ratio of string tensions between $q\bar{q}$ singlet and $qq$ antisymmetric potentials is described in terms of the Casimir factor.