论文标题
在QCD中的nnlo中朝向b-> x_s伽马无插值
Towards B -> X_s gamma at the NNLO in QCD without interpolation in m_c
论文作者
论文摘要
从B-> X_S Gamma分支比率加强对新物理的约束需要提高测量和标准模型预测的准确性。为了匹配预期的Belle-II准确性，必须计算近代到接头订单（NNLO）QCD校正，而无需在Charm-Quark Mass M_C中使用SO-FAR使用的插值。在评估M_C物理值的此类校正的过程中，我们最终确定了零件的零件，该零件是在GLUON线上封闭的Fermion循环的图表，这些零件有助于电流电流和光子偶极子操作员的干扰。我们确认了几个已发表的结果，以纠正这种类型，并用先前未算的作品补充它们。考虑到最近改进的非扰动贡献的估计值，我们发现b_ {s gamma} =（3.40 \ pm 0.17） * 10^{ - 4}和r_gamma = b _ {（s+d）gamma} gamma}/b_ {c l nu}腐烂的介子休息框架。
Strengthening constraints on new physics from the B -> X_s gamma branching ratio requires improving accuracy in the measurements and the Standard Model predictions. To match the expected Belle-II accuracy, Next-to-Next-to-Leading Order (NNLO) QCD corrections must be calculated without the so-far employed interpolation in the charm-quark mass m_c. In the process of evaluating such corrections at the physical value of m_c, we have finalized the part coming from diagrams with closed fermion loops on the gluon lines that contribute to the interference of the current-current and photonic dipole operators. We confirm several published results for corrections of this type, and supplement them with a previously uncalculated piece. Taking into account the recently improved estimates of non-perturbative contributions, we find B_{s gamma} = (3.40 \pm 0.17) * 10^{-4} and R_gamma = B_{(s+d) gamma}/B_{c l nu} = (3.35 \pm 0.16) * 10^{-3} for E_gamma > 1.6 GeV in the decaying meson rest frame.
