Computation of the Heavy-Light Decay Constant with NRQCD

TL;DR

This paper uses non-relativistic QCD on the lattice to compute the decay constant of heavy-light mesons, providing results for B mesons and their static limit with improved reliability.

Contribution

It presents a lattice computation of the heavy-light meson decay constant using NRQCD in quenched approximation, including a new estimate of the decay constant for B mesons.

Findings

Calculated $f_B$ as 164(17) MeV at $eta=6.0$

Estimated static limit decay constant as 247(26) MeV

Achieved clear signals for ground state in correlators

Abstract

Non-relativistic QCD is applied for a lattice computation of the heavy-light meson decay constant in quenched approximation at $\beta=6.0$. Clear signals are obtained for the ground state at large times in the correlators, allowing a reliable extraction of the decay constant. Estimating the current renormalization factor by the tadpole improvement procedure, we find $f_{B}=$ 164(17) MeV for the $B$ meson with $a^{-1}=$ 2.3 GeV, while an extrapolation to the static limit yields $f_{B}^{\mbox{static}}=$ 247(26) MeV.