Effective Yukawa Couplings in Noncompact Lattice QED

TL;DR

This paper studies how mesons couple to fermions in noncompact lattice QED, finding results consistent with perturbation theory and triviality of QED, especially at weak coupling.

Contribution

It provides the first detailed lattice QED analysis of effective Yukawa couplings using Monte Carlo simulations with dynamical fermions.

Findings

Yukawa couplings scale as expected from perturbation theory

Results support the triviality of QED at weak coupling

Consistency with other quantities' flows is observed at weak coupling

Abstract

We investigate effective Yukawa couplings of mesons to the elementary fermions in noncompact lattice QED. The couplings are extracted from suitable fermion-antifermion-meson three-point functions calculated by Monte Carlo simulations with dynamical staggered fermions. The scaling behaviour is compatible with expectations from perturbation theory, thus indicating triviality of QED. The lines of constant Yukawa coupling are compared to flows of other quantities. Consistency is seen, at most, for weak coupling.