B Meson Decay Constants Using Relativistic Heavy Quarks

Abstract

We present an update on ongoing work to extract pseudoscalar and vector decay constants for $B^{(\ast )}$, $B_s^{(\ast )}$ and $B_c^{(\ast )}$ mesons and determine phenomenologically-interesting ratios such as $f_{B_s}/f_B$ or $f_{B^{\ast }}/f_B$. Our calculation is based on ${\mathrm{N}}_{\mathrm{f}}=2+1$ dynamical flavour gauge field ensembles generated by the RBC/UKQCD collaborations using domain-wall fermions and the Iwasaki gauge action. Using domain-wall light, strange, and charm quarks and relativistic $b$ quarks, we obtain results at multiple lattice spacings and valence quark masses.

Comments: 10 pages, 5 figures, 1 table, Contribution to the 39th International Symposium on Lattice Field Theory, 8th-13th August, 2022, Bonn, Germany