$\overline{B}\to D^{\ast }\ell \overline{\hat{I}}½$ at non-zero recoil

Abstract

We present preliminary results from our analysis of the form factors for the $\overline{B}\to D^{\ast }\ell \overline{\hat{I}}½$ decay at non-zero recoil. Our analysis includes 15 MILC asqtad ensembles with $N_f=2+1$ flavors of sea quarks and lattice spacings ranging from $a\approx 0.15$ fm down to $0.045$ fm. The valence light quarks employ the asqtad action, whereas the heavy quarks are treated using the Fermilab action. We conclude with a discussion of future plans and phenomenological implications. When combined with experimental measurements of the decay rate, our calculation will enable a determination of the CKM matrix element $|V_{cb}|$.

8 pages, 5 figures, Proceedings of the talk presented at the 35th International Symposium on Lattice Field Theory (Lattice2017), Granada, Spain