Improvement of heavy-heavy current for calculation of B̅ → D^(*)lv̅ form factors using Oktay-Kronfeld heavy quarks

¹ Lattice Gauge Theory Research Center, CTP, Department of Physics and Astronomy, Seoul National University, Seoul 08826, South Korea
² Los Alamos National Laboratory, Theoretical Division T-2, Los Alamos, New Mexico 87545, USA
³ Brookhaven National Laboratory, Department of Physics, Upton, New York 11973, USA

^* e-mail: wlee@snu.ac.kr

Published online: 26 March 2018

Abstract

The CKM matrix element |V_cb| can be extracted by combining data from experiments with lattice QCD results for the semileptonic form factors for the B̅ → D(*)lv̅ 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.