Analysis of B <inf>d,s</inf> mixing angles in the presence of new physics and an update of B <inf>s</inf>→K ^̄0 ^*K0 ^*

We discuss a simple approach to measure the weak mixing angles s and d of the B s and B d systems in the presence of New Physics. We present a new expression that allows one to measure directly d,sNP if New Physics contributes significantly to the mixing only. We apply the method to specific penguin-mediated B→PP, B→PV and B→VV modes. We provide a very stringent and simple bound on the direct CP asymmetries of all these modes, the violation of which is a signal of New Physics in decay. Within the same theoretical framework, an updated prediction for the branching ratio of B s→K0 *K ̄0 * is presented, which can be compared with a recent LHCb analysis. © 2012 American Physical Society.