Lattice QCD calculation of form factors describing the rare decays B →k*+- and Bs →φ+-

The rare decays B0→K*0μ+μ- and Bs→φμ+μ- are now being observed with enough precision to test Standard Model predictions. A full understanding of these decays requires accurate determinations of the corresponding hadronic form factors. Here we present results of lattice QCD calculations of the B→K* and Bs→φ form factors. We also determine the form factors relevant for the decays Bs→K*ν and Bs→K̄*0+-. We use full-QCD configurations including 2+1 flavors of sea quarks using an improved staggered action, and we employ lattice nonrelativistic QCD to describe the bottom quark.