B → a0(1450)ϕ decays: dominated by the \U0001d6da–ϕ mixing in the standard model

Abstract

In the two-quark model supposition for the meson a0(1450), which can be viewed as either the first excited state (scenario I) or the lowest lying state (scenario II), the branching ratios and the direct CP-violating asymmetries for decays B− → a−0(1450)ϕ and are studied by employing the perturbative QCD factorization approach. We find the following results. (a) If we do not consider the ω–ϕ mixing, the decays and are highly suppressed by the Okubo–Zweig–Iizuka rule; their branching ratios are at the order of 10−9 in scenario I and even smaller in scenario II. (b) If the ω–ϕ mixing effect is included, the branching ratios can be dramatically enhanced, especially for the decay in scenario II, whose branching ratio arrives at the order of 10−8. In scenario I, the branching ratios are about a factor of 4–5 above the ones in the absence of ω–ϕ mixing. (c) For a more transparent comparison between the predictions and the data, we also calculate the ratio . Because it is less sensitive to the nonperturbative inputs, the large deviation of this ratio from the standard-model prediction could reveal a signal of new physics. (d) When the ω–ϕ mixing effect is included, the interference between the tree and the penguin contributions induces the direct CP violation, which is sensitive to the ω–ϕ mixing angle θ.