Towards more accurate $B_{(s)}\rightarrow\pi(K)$ and $D_{(s)}\rightarrow\pi(K)$ form factors

TL;DR

This paper reports progress in calculating various form factors for meson decays using lattice QCD with HISQ ensembles, covering a wide kinematic range and including physical quark masses.

Contribution

It introduces a comprehensive lattice QCD calculation of scalar, vector, and tensor form factors for multiple meson decays using the heavy-HISQ approach across different lattice spacings and quark masses.

Findings

Progress in form factor calculations for $B$ and $D$ meson decays.

Use of HISQ ensembles with physical and non-physical quark masses.

Coverage of the full kinematic range with relativistic heavy quarks.

Abstract

We present progress on the calculation of scalar, vector, and tensor form factors for the following meson decays: $B\rightarrow\pi$, $B_s\rightarrow K$, $D\rightarrow\pi$ and $D_s\rightarrow K$. This calculation uses the MILC HISQ gluon field ensembles with HISQ valence quarks. We generate ensembles of correlator data with varying lattice spacings, some as small as 0.044 fm. Some ensembles have a strange-to-light quark mass ratio of 5:1 and others use the physical light quark mass. The fully-relativistic, heavy-HISQ approach is used for the heavy quark, with simulation masses ranging from the charm to near the bottom. This heavy-HISQ approach provides nearly full coverage of the kinematic range.