Improvement of heavy-heavy current for calculation of B̄ → D(∗)lv̄ form factors using Oktay-Kronfeld heavy quarks

Abstract

© The Authors, published by EDP Sciences, 2018.The CKM matrix element |Vcb| can be extracted by combining data from experiments with lattice QCD results for the semileptonic form factors for the B̄ → D(∗)lv̄ decays. The Oktay-Kronfeld (OK) action was designed to reduce heavy-quark discretization errors to below 1%, or through O(λ3) in HQET power counting. Here we describe recent progress on bottom-to-charm currents improved to the same order in HQET as the OK action, and correct formerly reported results of our matching calculations, in which the operator basis was incomplete.