Chiral Symmetry Breaking and Meson Wave Functions in Soft-Wall AdS/QCD

TL;DR

This paper develops meson wave functions within soft-wall AdS/QCD that incorporate chiral symmetry breaking and heavy quark limits, accurately reproducing meson spectra and decay constants across light, heavy-light, and heavy quarkonia.

Contribution

It introduces a comprehensive framework for meson wave functions in soft-wall AdS/QCD that respects both chiral symmetry breaking and heavy quark limits, aligning with experimental and theoretical results.

Findings

Wave functions depend on quark mass, matching chiral symmetry breaking effects.

Correct mass spectra and splittings for heavy-light mesons.

Decay constants scale as predicted by QCD and potential models.

Abstract

We consider mesons composed of light and heavy quarks and discuss the construction of the corresponding meson wave functions in soft-wall AdS/QCD. We specifically take care that constraints imposed by chiral symmetry breaking and by the heavy quark limit are fulfilled. The main results are: i) the wave functions of light mesons have a nontrivial dependence on the current quark mass, which gives rise to a mass spectrum consistent with the one including explicit breaking of chiral symmetry; ii) the wave functions of heavy-light mesons generate their correct mass spectrum, the mass splittings of vector and pseudoscalar states, and the correct scaling of leptonic decay constants f(Q \bar q) \sim 1/sqrt(mQ); iii) the wave functions of heavy quarkonia produce their correct mass spectrum and lead to a scaling behaviour of the leptonic decay constants f(Q \bar Q) \sim sqrt(mQ) and f(c \bar b) \sim mc/sqrt(mb) at mc << mb, consistent with potential models and QCD sum rules.