Implications of the HyperCP data on B and τ decays

If the HyperCP three events for the decay of Σ+→pμ+μ−Σ+→pμ+μ− are explained by a new pseudoscalar (axial-vector) boson XP(A)XP(A) with a mass of 214.3 MeV, we study the constraints on the couplings between XP(A)XP(A) and fermions from the experimental data in K and B processes. Some implications of the new particle on flavor changing B and τ   decays are given. Explicitly, we show that the decay branching ratios of Bs→ϕXP(A)→ϕμ+μ−Bs→ϕXP(A)→ϕμ+μ−, Bd→K0∗(1430)P(A)→K0∗(1430)μ+μ− and τ→μXP(A)→μμ+μ−τ→μXP(A)→μμ+μ− can be as large as 2.7(2.8)×10−6, 7.4(7.5)×10−7 and 1.7(0.14)×10−7, respectively.