Studies of B and B_s Meson Leptonic Decays with NRQCD Bottom and HISQ Light/Strange Quarks

TL;DR

This paper reports on improved lattice QCD calculations of B and B_s meson decay constants using NRQCD for heavy quarks and HISQ for light quarks, achieving reduced discretization errors and precise current matching.

Contribution

It introduces new calculations employing NRQCD and HISQ quarks on MILC lattices with updated quark masses and one-loop current matching, enhancing accuracy over previous studies.

Findings

Significant reduction in discretization effects.

Updated quark mass tuning with new r_1 scale.

One-loop matching of axial vector current including dimension 4 corrections.

Abstract

We present a progress report on new calculations of B and B_s meson decay constants employing NRQCD heavy and HISQ light valence quarks and using MILC N_f = 2+1 AsqTad lattices. Bare quark masses have been retuned in accord with HPQCD's new r_1 scale. We find significant reductions in discretization effects compared to previous calculations with AsqTad light valence quarks. Matching of the NRQCD/HISQ heavy-light axial vector current is carried out at one-loop order including all relevant dimension 4 current corrections.