Positronium: an illustration of nonperturbative renormalization in a basis light-front approach

TL;DR

This paper demonstrates a nonperturbative renormalization approach within a basis light-front framework to compute the mass spectrum and wave functions of positronium and heavy mesons, advancing understanding of strong coupling regimes.

Contribution

It introduces a method for nonperturbative renormalization in a basis light-front approach applied to both QED and QCD systems, including fermion self-energy corrections.

Findings

Calculated positronium mass spectrum and wave functions.

Extended approach to heavy mesons in QCD.

Showed effective nonperturbative renormalization in strong coupling regimes.

Abstract

We calculate the mass spectrum and the structure of the positronium system at a strong coupling in a basis light-front approach. We start from the light-front QED Hamiltonian and retain one dynamical photon in our basis. We perform the fermion mass renormalization associated with the nonperturbative fermion self-energy correction. We present the resulting mass spectrum and wave functions for the selected low-lying states. Next, we apply this approach to QCD and calculate the heavy meson system with one dynamical gluon retained. We illustrate the obtained mass spectrum and wave functions for the selected low-lying states.