The mass of heavy-light mesons in a constituent quark picture with partially restored chiral symmetry

TL;DR

This paper investigates how partial restoration of chiral symmetry affects heavy-light meson masses using a constituent quark model, revealing a non-monotonic relationship influenced by quark mass and potential effects.

Contribution

It introduces a model analyzing the impact of chiral symmetry restoration on meson masses by varying the light quark constituent mass, highlighting a minimum mass point.

Findings

Heavy-light meson mass has a minimum near the vacuum constituent quark mass.

Meson mass increases as the constituent quark mass decreases, consistent with QCD sum rule results.

The interplay between quark mass and potential explains the non-monotonic behavior.

Abstract

We probe effects of the partial chiral symmetry restoration to the mass of heavy-light mesons in a constituent quark model by changing the constituent quark mass of the light quark. Due to the competing effect between the quark mass and the linearly rising potential, whose contribution to the energy increases as the quark mass decreases, the heavy-light meson mass has a minimum value near the constituent quark mass typically used in the vacuum. Hence, the meson mass increases as one decreases the constituent quark mass consistent with recent QCD sum rule analyses, which show an increasing $D$ meson mass as the chiral order parameter decreases.