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

We report the status of an ongoing lattice-QCD calculation of form factors for exclusive semileptonic decays of $B$ mesons with both charged currents ($Btopiell u$, $B_sto Kell u$) and neutral currents ($Btopiell^+ell^-$, $Bto Kell^+ell^-$). The results are important for constraining or revealing physics beyond the Standard Model. This work uses MILCs (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.