Speaker
Dr
Sungwoo Park
(Los Alamos National Laboratory)
Description
We update the calculation of $B \to D^\ast \ell \nu$ form factor at zero-recoil using the Oktay-Kronfeld (OK) action for bottom and charm quarks. Heavy quark action is nonperturbatively tuned. The flavor changing currents are improved to $\mathcal{O}(\lambda\approx \Lambda_{QCD}/2m_Q)$, $Q=b,c$ at tree-level in the HQET power counting. We use the HISQ action for the light spectator quark with several valence quark masses. The calculation is done on the $2+1+1$-flavor MILC HISQ ensembles at $a\approx 0.12$ and $0.09$ fm with pion mass $M_\pi \approx 310$ MeV. The excited state contamination in the matrix elements is controlled by using multi-state fits on correlators with multiple source-sink separations and stabilized using an empirical Bayesian technique.
Primary authors
Dr
Sungwoo Park
(Los Alamos National Laboratory)
Dr
Yong-Chull Jang
(Brookhaven National Laboratory)
Co-authors
Dr
Jaehoon Leem
(Seoul National University)
Dr
Jon A. Bailey
(Seoul National University)
Dr
Rajan Gupta
(Los Alamos National Lab)
Dr
Tanmoy Bhattacharya
(Los Alamos National Laboratory)
Prof.
Weonjong Lee
(Seoul National University)