Revisiting the $B^{0} \to π^{0}π^{0} $ decays in the perturbative QCD approach

Abstract

We recalculate the branching ratio and CP asymmetry for B0 (B 0 ) → π 0 π 0 decays in the Perturbative QCD approach. In this approach, we consider all the possible diagrams including non-factorizable contributions and annihilation contributions. We obtain Br( B0 (B 0 ) → π 0 π 0 ) = (1.17 +0.11 −0.12 ) × 10 −6 . Our result is in agreement with the latest measured branching ratio of B 0 → π 0 π 0 by the Belle and HFAG Collaborations. We also predict large direct CP asymmetry and mixing CP asymmetry in B 0 → π 0 π 0 decays, which can be tested by the coming Belle-II experiments.