Determination of the CP violating weak phase $\gamma$ from the Decays $B\to D\pi$

Abstract

We propose a new method to extract the CP violating weak phase $\gamma$ (the phase of $V_{ub}^{\ast }$) in the CKM paradigm of the Standard Model, using $B^{-}\to D^0{\pi }^{-}\to f{\pi }^{-}$ and $B^{-}\to {\bar{D}}^0{\pi }^{-}\to f{\pi }^{-}$ decays, where $f$ are final states such as $K^{+}{\pi }^{-}$, $K^{+}{\rho }^{-}$, $K\pi \pi$, {\it etc.} We also study the experimental feasibility of our new method. With possibility of new phases in the CKM matrix, we re-examine some of the previously proposed methods to determine $\gamma$, and find that it would be in principle possible to identify $\gamma$ and a new phase angle $\theta$ separately.

Comments: 12 pages, 1 figure, LaTex; the version to be published in European Physical Journal C