Heavy-light quark systems from the QCD instanton vacuum: $N_f=1$ light flavor case

TL;DR

This paper models heavy-light mesons using the QCD instanton vacuum, deriving effective interactions and calculating meson masses and decay constants that align well with lattice QCD and experimental data.

Contribution

It introduces a novel approach to heavy-light meson properties using the QCD instanton vacuum, deriving effective interactions and computing observables.

Findings

Calculated $D$ and $B$ meson masses and decay constants.

Results for $f_D$ and $f_B$ agree with lattice QCD and PDG data.

Provided a framework connecting instanton effects to heavy-light meson phenomenology.

Abstract

We investigate heavy-light quark systems within the framework of the QCD instanton vacuum, focusing on the $N_f = 1$ light flavor case. We derive an effective heavy-light quark interaction from the low-energy QCD partition function and construct a heavy-meson effective Lagrangian. The physical residual mass of heavy mesons, $\Lambda$, is determined by employing compositeness and normalization conditions. We calculate the masses of $D$ and $B$ mesons and their weak decay constants to the leading order and next-to-leading order in the $1/m_Q$ expansion. The current results for $f_D$ and $f_B$ are in good agreement with recent lattice QCD data and PDG average values.