In the framework of factorization, we study direct CP violation in the decays of B(s) → J/ψP(V) (P(V) refer to the pseudoscalar (vector) meson). The CP violation depends strongly on Cabibbo-Kobayashi- Maskawa (CKM) matrix elements and the effective parameter, Nc. The recent experimental data for the branching ratios of B(s) → J/ψP(V) are accurate enough and we can give a strong constraint on the range of Nc. We find that the CP violating asymmetry is consistent with the available experiment values for the b → d transition, and a little smaller than the b → s transition. We also predict the CP violation of other decay channels for B(s) → J/ψP(V). We expect our results can give valuable guidance for experiments.
The spin is an important property of a particle. Although it is unlikely, there is still a possibility that two particles with different spins share similar masses. In this paper, we propose a method to probe this kind of mass degeneracy of particles with different spins. We use the cascade decay B+→X(3872)K+, X(3872)→D+D-to illustrate our method. It can be seen that the possible mass degeneracy of X(3872) can lead to interesting behavior in the corresponding cascade decay.
