Study of $CP$ Violating Effects in Time Dependent ${B}^{0}({\stackrel{\ifmmode \bar{}\else \={}\fi{}}{B}}^{0})\ensuremath{\rightarrow}{D}^{(*)\ensuremath{\mp}}{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$ Decays

Study of $C P$ Violating Effects in Time Dependent $B^{0} ({\bar{B}}^{0}) \to D^{(*) \mp} π^{\pm}$ Decays

T. R. Sarangi et al. (Belle Collaboration)

Phys. Rev. Lett. 93, 031802 – Published 13 July 2004

Abstract

We report measurements of time dependent decay rates for $B^{0} ({\bar{B}}^{0}) \to D^{(*) \mp} π^{\pm}$ decays and extraction of $C P$ violation parameters containing $ϕ_{3}$ . Using fully reconstructed $D^{(*)} π$ events from a $140 {f b}^{- 1}$ data sample collected at the $Υ (4 S)$ resonance, we obtain the $C P$ violation parameters for $D^{*} π$ and $D π$ decays, $2 R_{D^{(*)} π} \sin (2 ϕ_{1} + ϕ_{3} \pm δ_{D^{(*)} π})$ , where $R_{D^{(*)} π}$ is the ratio of the magnitudes of the doubly Cabibbo-suppressed and Cabibbo-favored amplitudes, and $δ_{D^{(*)} π}$ is the strong phase difference between them. Under the assumption of $δ_{D^{(*)} π}$ being close to either $0 °$ or $180 °$ , we obtain $| 2 R_{D^{*} π} \sin (2 ϕ_{1} + ϕ_{3}) | = 0.060 \pm 0.040 (s t a t) \pm 0.019 (s y s t)$ and $| 2 R_{D π} \sin (2 ϕ_{1} + ϕ_{3}) | = 0.061 \pm 0.037 (s t a t) \pm 0.018 (s y s t)$ .