On a clean determination of ${\varphi }_2$

Abstract

We point out that time dependent study of four decay modes $B^0(t)\to \Dbar K_S$, $B^0(t)\to D{K}_S$ $\Bbar^0(t)\to \Dbar K_S$, and $\Bbar^0(t)\to D K_S$ allows us to measure $\sin ({\varphi }_1-{\varphi }_2)$ - contrary to previously obtained result that it measures $\sin (2{\varphi }_1+{\varphi }_3)$. The time dependent study of $B_s^0(t)\to D_s^{\pm }{K}^{\mp }$, and the study of $B^-\to K^-(D,\Dbar)\to K^-f$ decay where $D\to f$ is a doubly Cabibbo suppressed decay yield information on ${\varphi }_3$, as previusly expected.

6 pages 2 figures