Precise B, B_s and B_c meson spectroscopy from full lattice QCD

TL;DR

This paper provides the first precise lattice QCD calculations of B, Bs, and Bc meson masses, achieving around 10 MeV accuracy and including sea quark effects, serving as parameter-free tests of QCD.

Contribution

First accurate lattice QCD results for B, Bs, and Bc meson masses including sea quark effects, with improved methods and parameter tuning.

Findings

Measured meson masses with ~10 MeV accuracy

Scalar and axial vector mesons are below decay thresholds

Results serve as parameter-free tests of QCD

Abstract

We give the first accurate results for $B$ and $B_s$ meson masses from lattice QCD including the effect of $u$, $d$ and $s$ sea quarks, and we improve an earlier value for the $B_c$ meson mass. By using the Highly Improved Staggered Quark action for $u/d$, $s$ and $c$ quarks and NRQCD for the $b$ quarks, we are able to achieve an accuracy in the masses of around 10 MeV. Our results are: $m_B$ = 5.291(18) GeV, $m_{B_s}$ = 5.363(11) GeV and $m_{B_c}$ = 6.280(10) GeV. Note that all QCD parameters here are tuned from other calculations, so these are parameter free tests of QCD against experiment. We also give scalar, $B_{s0}^*$, and axial vector, $B_{s1}$, meson masses. We find these to be slightly below threshold for decay to $BK$ and $B^*K$ respectively.