Semileptonic $B$-meson decays to light pseudoscalar mesons on the HISQ ensembles

TL;DR

This paper reports on ongoing lattice-QCD calculations of form factors for semileptonic B-meson decays to light pseudoscalar mesons, which are crucial for testing the Standard Model and exploring new physics.

Contribution

It introduces a calculation of B-meson decay form factors using HISQ ensembles with multiple lattice spacings and quark masses, advancing the precision of theoretical predictions.

Findings

Preliminary correlation-function fit results presented.

Simulations include physical and unphysical sea-quark masses.

Lattice spacings down to 0.088 fm used.

Abstract

We report the status of an ongoing lattice-QCD calculation of form factors for exclusive semileptonic decays of $B$ mesons with both charged currents ($B\to\pi\ell\nu$, $B_s\to K\ell\nu$) and neutral currents ($B\to\pi\ell^+\ell^-$, $B\to K\ell^+\ell^-$). The results are important for constraining or revealing physics beyond the Standard Model. This work uses MILC's (2+1+1)-flavor ensembles with the HISQ action for the sea and light valence quarks and the clover action in the Fermilab interpretation for the $b$ quark. Simulations are carried out at three lattice spacings down to $0.088$ fm, with both physical and unphysical sea-quark masses. We present preliminary results for correlation-function fits.