Symmetry-preserving contact interaction model for heavy-light mesons

TL;DR

This paper introduces a symmetry-preserving regularization method for a contact interaction model in low-energy QCD, enabling accurate study of heavy-light mesons while maintaining fundamental symmetries.

Contribution

The paper develops a subtraction-based regularization scheme that preserves symmetries in contact interaction models, applied to heavy-light mesons within Dyson-Schwinger and Bethe-Salpeter frameworks.

Findings

Successfully solved Dyson-Schwinger equations for u, d, s quark propagators.

Obtained Bethe-Salpeter amplitudes satisfying Ward-Green-Takahashi identities.

Applied method to pseudoscalar pion and Kaon mesons.

Abstract

We use a symmetry-preserving regularization method of ultraviolet divergences in a vector-vector contact interac- tion model for low-energy QCD. The contact interaction is a representation of nonperturbative kernels used Dyson-Schwinger and Bethe-Salpeter equations. The regularization method is based on a subtraction scheme that avoids standard steps in the evaluation of divergent integrals that invariably lead to symmetry violation. Aiming at the study of heavy-light mesons, we have implemented the method to the pseudoscalar pion and Kaon mesons. We have solved the Dyson-Schwinger equation for the u, d and s quark propagators, and obtained the bound-state Bethe-Salpeter amplitudes in a way that the Ward-Green-Takahashi identities reflecting global symmetries of the model are satisfied for arbitrary routing of the momenta running in loop integrals.