$B^0(\pm )$ decays into two vector mesons. Physical motivations and a general method for simulations

In this paper, a complete description of the channels $B\to V_1{V}_2$ is given. Emphasis is put on the determination of the dynamical density matrix which elements are computed according to the Wilson operator product expansions entering into the formulation of the weak effective hamiltonian. \vskip 0.3cm Kinematical consequences related to the particular channel $B \to K^* {\rho}^0 (\omega)$ are described in details.