Toward accurate form factors for $B$-to-light meson decay from lattice QCD

Understand

We present the results of a lattice QCD calculation of the scalar and vector form factors for the unphysical $B_s\to\eta_s$ decay, over the full physical range of $q^2$.

• This is a useful testing ground both for lattice QCD and for our wider understanding of the behaviour of form factors.
• Calculations were performed using the highly improved staggered quark (HISQ) action on $N_f = 2 + 1 + 1$ gluon ensembles generated by the MILC Collaboration with an improved gluon action and HISQ sea quarks.
• We use three lattice spacings and a range of heavy quark masses from that of charm to bottom, all in the HISQ formalism.