Heavy-meson semileptonic decays for the Standard Model and beyond

Abstract

We calculate the form factors for the semileptonic decays $B_s\to K\ell \nu$ and $B\to K\ell \ell$ with lattice QCD. We work at several lattice spacings and a range of light quark masses, using the MILC 2+1-flavor asqtad ensembles. We use the Fermilab method for the $b$ quark. We obtain chiral-continuum extrapolations for $E_K$ up to $\sim 1.2$ GeV and then extend to the entire kinematic range with the model-independent $z$ expansion.

Comments: 7. pp, 6 figs. Presented at the 31st International Symposium on Lattice Field Theory - LATTICE 2013, July 29 - August 3, 2013, Mainz, Germany