Variational calculation of heavy-light meson properties

TL;DR

This paper introduces a new variational method using maximal operator smearing in lattice QCD to efficiently study heavy-light meson properties, including decay constants and wave functions.

Contribution

The paper presents a novel variational approach with maximal operator smearing for better isolation of meson states in lattice QCD calculations.

Findings

Preliminary results for $f_{B}^{ m stat}$ decay constant.

Binding energies and wave functions of lowest states.

Effective eigenstate projection at small time separations.

Abstract

We present a new method for the study of heavy-light mesons in the static approximation of lattice QCD which is optimally effective in isolating ground and excited states. With ``MOST'' (Maximal Operator Smearing Technique), the heavy quark is smeared at all possible positions relative to the light quark, subject to the constraint of cubic symmetry. With correlation functions constructed using this set as a variational basis, eigenstates of the transfer matrix are projected out at very small time separations, where statistical errors are small. We illustrate the utility of the method with preliminary results for the meson decay constant $f_{B}^{\rm stat}$, binding energies and wave functions of the lowest states. The method produces dynamically-improved interpolating fields which can be used for matrix element calculations.