Heavy and heavy-light mesons in the Covariant Spectator Theory

TL;DR

This paper calculates heavy and heavy-light meson properties using the Covariant Spectator Theory, exploring the Lorentz structure of the confining interaction and comparing wave functions with light-front approaches.

Contribution

It introduces a detailed calculation of meson spectra within CST with a flexible kernel and compares CST wave functions to light-front results, providing new insights into meson structure.

Findings

CST accurately reproduces meson spectra.

Wave functions agree with light-front approaches.

Insights into Lorentz structure of the confining kernel.

Abstract

The masses and vertex functions of heavy and heavy-light mesons, described as quark-antiquark bound states, are calculated with the Covariant Spectator Theory (CST). We use a kernel with an adjustable mixture of Lorentz scalar, pseudoscalar, and vector linear confining interaction, together with a one-gluon-exchange kernel. A series of fits to the heavy and heavy-light meson spectrum were calculated, and we discuss what conclusions can be drawn from it, especially about the Lorentz structure of the kernel. We also apply the Brodsky-Huang-Lepage prescription to express the CST wave functions for heavy quarkonia in terms of light-front variables. They agree remarkably well with light-front wave functions obtained in the Hamiltonian basis light-front quantization (BLFQ) approach, even in excited states.