标题： 从 B \to a_0(1450)K^* 衰变中研究标量介子 a_0(1450) 显示英文标题

标题： Study of scalar meson a_0(1450) from B \to a_0(1450)K^* Decays

摘要： 在介子$a_0(1450)$的两夸克模型假设中，可以将其视为第一激发态（情景 I）或最低激发态（情景 II），通过采用微扰 QCD 因子化方法研究了衰变$B^-\to a^{0}_0(1450)K^{*-}, a^{-}_0(1450)K^{*0}$和$\bar B^0\to a^{+}_0(1450)K^{*-}, a^{0}_0(1450)\bar K^{*0}$的分支比和直接 CP 破坏不对称性。我们发现以下结果：(a) 对于衰变$B^-\to a^{-}_0(1450)K^{*0}, \bar B^0\to a^{+}_0(1450)K^{*-}, a^{0}_0(1450)\bar K^{*0}$，情景 II 中的分支比比情景 I 大约一个数量级。因此，实验上很容易区分介子$a_0(1450)$的情景 I 和 II。 (b) 对于衰变$B^-\to a^{0}_0(1450)K^{*-}$，由于没有接收到来自$K^*-$辐射因子化图的增强，其penguin算符贡献在场景II中是最小的，这使其分支比降至$10^{-6}$的量级。即使如此，场景II中的分支比仍比场景I中的大约2.5倍。 (c) 尽管我们的预测远大于QCD因子化结果的预测，但由于湮灭图的大理论误差，它们之间仍然一致。 (d) 我们预测衰变$B^-\to a^{-}_0(1450)K^{*0}$的直接CP破坏不对称性很小，仅几个百分比。 显示英文摘要

摘要： In the two-quark model supposition for the meson $a_0(1450)$, 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 $B^-\to a^{0}_0(1450)K^{*-}, a^{-}_0(1450)K^{*0}$ and $\bar B^0\to a^{+}_0(1450)K^{*-}, a^{0}_0(1450)\bar K^{*0}$ are studied by employing the perturbative QCD factorization approach. We find the following results: (a) For the decays $B^-\to a^{-}_0(1450)K^{*0}, \bar B^0\to a^{+}_0(1450)K^{*-}, a^{0}_0(1450)\bar K^{*0}$, their branching ratios in scenario II are larger than those in scenario I about one order. So it is easy for the experiments to differentiate between the scenario I and II for the meson $a_0(1450)$. (b)For the decay $B^-\to a^{0}_0(1450)K^{*-}$, due to not receiving the enhancement from the $K^*-$emission factorizable diagrams, its penguin operator contributions are the smallest in scenario II, which makes its branching ratio drop into the order of $10^{-6}$. Even so, its branching ratio in scenario II is still larger than that in scenario I about 2.5 times. (c) Even though our predictions are much larger than those from the QCD factorization results, they are still consistent with each other within the large theoretical errors from the annihilation diagrams. (d) We predict the direct CP- violating asymmetry of the decay $B^-\to a^{-}_0(1450)K^{*0}$ is small and only a few percent.