Investigating the Effect of Family Non-universal Z′ Boson in B → ϕϕ Decay

الأصل · EN

Within the perturbative QCD approach, we re-calculate the branching ratio and polarization fractions of the pure annihilation decay B → ϕϕ in both the standard model (SM) and the family non-universal Z′ model. We find that this decay is dominated by the longitudinal part, while the transverse parts are negligibly due to the absence of the (S-P)(S+P)-type operator. In SM, the branching ratio is predicted as (4.4⁺⁰.⁸⁺⁰.³₋₀.₆₋₀.₅) × 10⁻⁸, which is larger than the previous predictions. With an additional Z′ boson, the branching ratio can be enhanced by a factor of 2, or reduced one half in the allowed parameters space. These results will be tested by the ongoing LHCb experiment and forthcoming Super-B experiments. Moreover, if the Z′ boson could be directly detected at hadron collider, this decay can be used to constrain its mass and the couplings in turn.