NLO QCD corrections to the lifetime ratio B(plus)/Bd

在重夸克展开框架下计算了带电和中性B介子寿命分裂的微扰QCD修正。这些次领先的对数校正是必要的一个有意义的使用强子矩阵元的局部运营商从格点规范理论。我们发现与重正化尺度和方案的选择相关的不确定性显着减少相比，领先的顺序的结果。我们包括了对粲夸克质量mc的完全依赖，而没有任何近似。利用文献中用格点QCD估计的强子矩阵元，我们得到t（B+）/t（B_0）= 1.053 ± 0.027 ± 0.017，其中还不包括非猝灭和1/mb修正的影响。本文还简要讨论了重子X_0和X_-的寿命差异。

We compute perturbative QCD corrections to the lifetime splitting between the charged and neutral B meson in the framework of the heavy quark expansion. These next-to-leading logarithmic corrections are necessary for a meaningful use of hadronic matrix elements of local operators from lattice gauge theory. We find the uncertainties associated with the choices of renormalization scale and scheme significantly reduced compared to the leading-order result. We include the full dependence on the charm-quark mass mc without any approximations. Using hadronic matrix elements estimated in the literature with lattice QCD we obtain t(B+)/t(B0) = 1.053 ± 0.027 ± 0.017, where the effects of unquenching and 1/mb corrections are not yet included. The lifetime difference of heavy baryons X0 and X- is also briefly discussed.