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

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 ($B\to \ddot{I}€\ell \hat{I}½$, $B_s\to K\ell \hat{I}½$) and neutral currents ($B\to \ddot{I}€{\ell }^{+}{\ell }^{-}$, $B\to K{\ell }^{+}{\ell }^{-}$). 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.

8 pages, 3 figures; presented at the 35th International Symposium on Lattice Field Theory, 18-24 June 2017, Granada, Spain