Calculation of $\bar{B}\to D^{\ast }\ell \bar{\nu }$ form factor at zero recoil using the Oktay-Kronfeld action

Abstract

We present the first preliminary results for the semileptonic form factor $h_{A_1}(w=1)/{\rho }_{A_j}$ at zero recoil for the $\bar{B}\to D^{\ast }\ell \bar{\nu }$ decay using lattice QCD with four flavors of sea quarks. We use the HISQ staggered action for the light valence and sea quarks (the MILC HISQ configurations), and the Oktay-Kronfeld (OK) action for the heavy valence quarks.

8 pages, 7 figures, Lattice 2017 proceeding, references updated