Meson-meson interactions -- from static to dynamic valence quarks

TL;DR

This paper introduces a method to extract effective meson-meson potentials from lattice Green functions, analyzing static and dynamic quark effects in QED and QCD simulations.

Contribution

It presents a novel approach to derive meson-meson interactions from lattice data, including static and dynamical quark effects, using quenched approximation and advanced algorithms.

Findings

QED shows a hard core due to Pauli exclusion

QCD exhibits strong attraction at small distances

Method applicable to lattice simulations of meson interactions

Abstract

A method for the extraction of an effective meson-meson potential from Green functions, which can be obtained from a lattice simulation, is presented. Simulations are carried out for compact QED and QCD in four dimensions using the quenched approximation and the hopping parameter expansion. In a further study, a heavy-light meson is considered employing a conjugate gradient algorithm for the light propagators. Due to the Pauli exclusion principle, the results for QED indicate the existence of a hard core, but for QCD there is strong attraction at small meson distances.