$|V_{ub}|$ determination by $B \to D_s \pi$

Abstract

We investigate \ovar{B^0} \to D_s^- \pi^+ decay in perturbative QCD approach which has recently been applied to $B$ meson decays. \ovar{B^0} \to D_s^- \pi^+ decay (and its charge conjugated mode) can be one of the hopeful modes to determine $|V_{ub}|$ since it occurs through $b \to u$ transition only. We estimate both factorizable and non-factorizable contribution, and show that the non-factorizable contribution is much less than the factorizable one. Our calculation gives {BR}(\ovar{B^0} \to D_s^- \pi^+) = (50 \sim 70) \times f_{Ds}^2|{V_{ub}}{V_{cs}}|^2.Comment: 12 pages, 3 figures, LaTeX2e with graphics packag