Determining the CP-violating phase

The weak phase 7 is conventionally probed by the B ~ p ~ mode. The predicted rate is tiny. Even if a B~-4p~ rate difference could be established, it would not be clear that sin 27 had been measured, because amplitudes with other weak phases may contribute significantly. Non-CP eigenstates, such as B ~ D ~ K -v, have a two-fold advantage over Bs~p~ Their rates are orders of magnitude above that for B~--*p~ and they probe the CP-violating phase 7, without any contamination from other weak phases. Detailed time-dependent studies of non-CP eigenstates remove possible final-state phases and extract the weak phase 7.