论文标题
$λ_b\rightarrowλ_cπ，λ_ck$在扰动QCD方法中
Nonleptonic two-body decays of $Λ_b\rightarrow Λ_c π, Λ_cK$ in the perturbative QCD approach
论文作者
论文摘要
我们研究了颜色允许的$λ_b\rightArrowλ_cπ，λ_ck$ pers the扰动QCD方法（PQCD）以最低顺序以强耦合常数$α_s$。在我们的计算中考虑了可因素和不可分割的贡献。发现这些过程以可分解的贡献为主，而重要的不可分割的贡献可以提高分支比率约30 $ \％$。衰减分支比率预计为$ \ MATHCAL {B}（λ_b\rightArrowλ_cπ）= 6.7^{+4.1} _ { - 3.8} \ times 10^{ - 3} { - 3} $和$ \ MATHCAL {b}（λ_b}（λ_b\rightarrowλ_c） k）= 5.0^{+4.0} _ { - 3.0} \ times 10^{ - 4} $，其中不确定性来自Baryon Light-Cone分布振幅（LCDAS），沉重的Charm Quark和Charm Quark和Charmed Baryon Masses和硬尺度。结果表明，这两个衰减中的不对称参数大约等于-1，预期的是在重夸克极限和软中膜限制中。我们的预测与错误中的最新实验数据一致。在可用时，还将获得的数值结果与其他理论方法中的数值结果进行了比较。
We study the color-allowed $Λ_b\rightarrow Λ_c π, Λ_cK$ decays in the perturbative QCD approach (PQCD) to lowest order in strong coupling constant $α_s$. Both the factorizable and nonfactorizable contributions are taken into account in our calculations. It is found that these processes are dominated by the factorizable contributions, while the important nonfactorizable contributions can enhance the branching ratios by about 30$\%$. The decay branching ratios are predicted to be $\mathcal{B}(Λ_b\rightarrow Λ_c π)=6.7^{+4.1}_{-3.8}\times 10^{-3}$ and $\mathcal{B}(Λ_b\rightarrow Λ_c K)=5.0^{+4.0}_{-3.0}\times 10^{-4}$, where the uncertainties arise from the baryon light-cone distribution amplitudes (LCDAs), the heavy charm quark and charmed baryon masses, and the hard scales. It is shown that the asymmetry parameters in the two decays are approximately equal to -1, which is expected as in the heavy quark limit and the soft meson limit. Our predictions are consistent with the recent experimental data within errors. The obtained numerical results are also compared to those in the other theoretical approaches when they are available.
