Semileptonic $B \to D^{(\ast)} \ellν$ Decay Form Factors using the Oktay-Kronfeld Action

• DOI: 10.48550/arxiv.2003.09206
• Publication Date: 2020-01-01
• Authors: Bhattacharya, Tanmoy; Choi, Benjamin J.; Gupta, Rajan; Jang, Yong-Chull; Jwa, Seungyeob; Lee, Sunkyu; Lee, Weonjong; Leem, Jaehoon; Park, Sungwoo
• Keywords: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Lattice (hep-lat); FOS: Physical sciences

We report recent progress in calculating semileptonic form factors for the $\bar{B} \to D^\ast \ell \barν$ and $\bar{B} \to D \ell \barν$ decays using the Oktay-Kronfeld (OK) action for bottom and charm quarks. We use the second order in heavy quark effective power counting $\mathcal{O}(λ^2)$ improved currents in this work. The HISQ action is used for the light spectator quarks. We analyzed four $2+1+1$-flavor MILC HISQ ensembles with $a\approx 0.09\,\mathrm{fm}$, $0.12\,\mathrm{fm}$ and $M_π\approx 220\,\mathrm{MeV}$, $310\,\mathrm{MeV}$: $a09m220$, $a09m310$, $a12m220$, $a12m310$. Preliminary results for $B\to D^\ast\ellν$ decays form factor $h_{A_1}(w)$ at zero recoil ($w=1$) are reported. Preliminary results for $B \to D\,\ellν$ decays form factors $h_\pm(w)$ over a kinematic range $1<br/>7 pages, 7 figures, Lattice 2019 proceeding<br/>