On the nature of the residual meson-meson interaction from simulations with a QED${}_{2+1}$ model

TL;DR

This paper investigates the meson-meson interaction potential in a 2+1 dimensional QED lattice model, revealing a short-range repulsion and dipole-induced attraction, with sea quarks softening the potential.

Contribution

It provides a detailed extraction of the meson-meson potential from lattice simulations in a confining QED model, highlighting the effects of dynamical fermions.

Findings

Meson-meson potential has a short-range repulsive core.

Dipole-dipole forces cause attraction at intermediate distances.

Sea quarks soften the overall potential.

Abstract

A potential between mesons is extracted from 4-point functions within lattice gauge theory taking 2+1 dimensional QED as an example. This theory possesses confinement and dynamical fermions. The resulting meson-meson potential has a short-ranged hard repulsive core and the expected dipole-dipole forces lead to attraction at intermediate distances. Sea quarks lead to a softer form of the total potential.