Neutral B meson mixing with static heavy and domain-wall light quarks

TL;DR

This paper calculates B meson mixing matrix elements and decay constants using static b quarks and domain-wall light quarks on dynamical lattice ensembles, providing precise results for SU(3) breaking ratios.

Contribution

It introduces a lattice QCD calculation of B meson mixing with static b quarks and domain-wall light quarks, including continuum extrapolation and perturbative matching.

Findings

SU(3) breaking ratio b3=1.222(60) in the static limit

Use of link-smearings improves signal-to-noise ratio

Results combined from two link-smearing methods for continuum limit

Abstract

Neutral B meson mixing matrix elements and B meson decay constants are calculated. Static approximation is used for b quark and domain-wall fermion formalism is employed for light quarks. The calculations are done on 2+1 flavor dynamical ensembles, whose lattice spacings are 0.086 fm and 0.11 fm with a fixed physical spatial volume of about (2.7 fm)^3. In the static quark action, link-smearings are used to improve the signal-to-noise ratio. We employ two kinds of link-smearings and their results are combined in taking a continuum limit. For the matching between the lattice and the continuum theory, one-loop perturbative calculations are used including O(a) improvements to reduce discretization errors. We obtain SU(3) braking ratio \xi=1.222(60) in the static limit of b quark.