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

在重夸克展开的框架下，我们计算了带电B介子和中性B介子寿命分裂的微扰QCD修正。这些近乎领先的对数修正对于从格点规范理论中有意义地使用局域算符的强子矩阵元是必要的。我们发现，与前序结果相比，与重整化尺度和格式的选择相关的不确定性显著降低。我们包含了对魅力夸克质量MC的完全依赖，没有任何近似。利用文献中用晶格QCD估计的强子矩阵元，我们得到t(B+)/t(B0)=1.053±0.027±0.017，其中还没有考虑非猝灭和1/mb修正的影响。文中还简要讨论了重子X0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.