We study the rates and direct $CP$ violations of two-body baryonic ${\overline{B}}_{u,d,s}\to {\mathbf{\text{B}}\overline{\mathbf{\text{B}}}}^{\prime }$ and $B_c^{-}\to {\mathbf{\text{B}}\overline{\mathbf{\text{B}}}}^{\prime }$ decays, where the final state baryons include low-lying octet and decuplet baryons. We incorporate topological amplitude formalism and the factorization approach. Asymptotic relations at large $m_b$ are used to simplify decay amplitudes. Using the most up-to-date data on ${\overline{B}}^0\to p\overline{p}$ and $B^{-}\to \mathrm{\Lambda }\overline{p}$ decay rates as inputs, rates and direct $CP$ violations of ${\overline{B}}_{u,d,s}\to {\mathbf{\text{B}}\overline{\mathbf{\text{B}}}}^{\prime }$ decays are revised and predicted. It is interesting that the results on rates satisfy all existing experimental bounds and some are close to the bounds. Factorization diagrams contribute to penguin-exchange, exchange, annihilation, and penguin-annihilation amplitudes. Although the resulting penguin-exchange factorization amplitudes are sizable, the rest suffer from severe chiral suppression and are sensitive to nonfactorizable contributions. As the ${\overline{B}}_s\to p\overline{p}$ decay is governed by exchange and penguin annihilation amplitudes, the rate predicted in factorization calculation is very rare, but it can be enhanced by including nonfactorizable contributions. The case where the rate is enhanced to saturate the present experimental bound through the enhancement on exchange or penguin-annihilation amplitudes is discussed. As annihilation modes $B_c^{-}\to {\mathbf{\text{B}}\overline{\mathbf{\text{B}}}}^{\prime }$ decays from factorization calculation are found to be very rare, but they can be enhanced by including nonfactorizable contributions as well. Small direct $CP$ violations of pure penguin modes in $\mathrm{\Delta }S=-1$ ${\overline{B}}_{u,d,s}\to {\mathbf{\text{B}}\overline{\mathbf{\text{B}}}}^{\prime }$ decays are robust predictions of the SM, while vanishing direct $CP$ violations of exchange modes in ${\overline{B}}_{u,d,s}\to {\mathbf{\text{B}}\overline{\mathbf{\text{B}}}}^{\prime }$ decays and in all $B_c^{-}\to {\mathbf{\text{B}}\overline{\mathbf{\text{B}}}}^{\prime }$ decay modes are null tests of the SM.

中文翻译：

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二体重子Bu,d,sandBcto 无粲终态衰变

我们研究费率并直接$C磷$违反二体重子${\overline{乙}}_{你,d,s}\to {\mathbf{\text{乙}}\overline{\mathbf{\text{乙}}}}^{\text{'}}$和${乙}_C^{-}\to {\mathbf{\text{乙}}\overline{\mathbf{\text{乙}}}}^{\text{'}}$衰变，其中最终状态重子包括低位八重子和十重子重子。我们结合了拓扑振幅形式主义和分解方法。渐近关系${米}_b$用于简化衰减幅度。使用最新的数据${\overline{乙}}^0\to p\overline{p}$和${乙}^{-}\to \mathrm{\Lambda }\overline{p}$衰减率作为输入、率和直接$C磷$违反${\overline{乙}}_{你,d,s}\to {\mathbf{\text{乙}}\overline{\mathbf{\text{乙}}}}^{\text{'}}$衰变被修正和预测。有趣的是，速率的结果满足所有现有的实验界限，有些接近界限。因式分解图有助于企鹅交换、交换、湮没和企鹅湮没幅度。尽管由此产生的企鹅交换因子分解幅度相当大，但其余的都受到严重的手性抑制并且对不可分解的贡献敏感。作为${\overline{乙}}_s\to p\overline{p}$衰减受交换幅度和企鹅湮没幅度控制，分解计算中预测的速率非常罕见，但可以通过包括不可分解的贡献来增强。讨论了通过增强交换或企鹅湮没振幅来增强速率以使当前实验界限饱和的情况。作为歼灭模式${乙}_C^{-}\to {\mathbf{\text{乙}}\overline{\mathbf{\text{乙}}}}^{\text{'}}$分解计算的衰减被发现非常罕见，但它们也可以通过包括不可分解的贡献来增强。小直$C磷$违反纯企鹅模式$\mathrm{\Delta }\mathrm{小号}=-1$ ${\overline{乙}}_{你,d,s}\to {\mathbf{\text{乙}}\overline{\mathbf{\text{乙}}}}^{\text{'}}$衰减是对 SM 的稳健预测，而直接消失$C磷$违反交换模式${\overline{乙}}_{你,d,s}\to {\mathbf{\text{乙}}\overline{\mathbf{\text{乙}}}}^{\text{'}}$腐烂，在所有${乙}_C^{-}\to {\mathbf{\text{乙}}\overline{\mathbf{\text{乙}}}}^{\text{'}}$衰减模式是 SM 的无效测试。