论文标题
双辐射底 - 中膜衰变的精确计算在软共线有效理论中
Precision calculations of the double radiative bottom-meson decays in soft-collinear effective theory
论文作者
论文摘要
采用软共线有效理论的系统框架（SCET），我们对重型夸克扩展中的双辐射式$ b_ {d，\，\，\，\，\，\，\，\，\，\，\，\，\，\，\，\，S} $进行了改进的计算。然后，我们构建QCD分解公式，用于由底部介子在树水平的底部介子组成的光弹性夸克夸克辐射产生的二级功率贡献。此外，我们探索了从有效的cent Current $ j^{（a2）} $ at $ {\ cal o}（α_s^0）$的有效cent $ j^{（a2）} $的分解属性。对$ b_ {d，\，s} \对γγ$螺旋形式的高度贡献从两粒子和三粒子底部 - 梅森分布振幅中进行了评估，并以扭曲六的精度进行评估。此外，以一环准确性考虑了当前电流和QCD企鹅运算符的转向功率弱压力贡献。我们继续应用操作员生产 - 膨胀控制的分散关系，以估计对双辐射$ b_ {d，\，\，s} $ - 梅森衰减形式的功率抑制的软贡献。 Phenomenological explorations of the radiative $B_{d, \, s} \to γ\, γ$ decay observables in the presence of the neutral-meson mixing, including the CP-averaged branching fractions, the polarization fractions and the time-dependent CP asymmetries, are carried out subsequently with an emphasis on the numerical impacts of the newly computed ingredients together with从HQET底部 - 梅森分布幅度的形状参数中的理论不确定性。
Employing the systematic framework of soft-collinear effective theory (SCET) we perform an improved calculation of the leading-power contributions to the double radiative $B_{d, \, s}$-meson decay amplitudes in the heavy quark expansion. We then construct the QCD factorization formulae for the subleading power contributions arising from the energetic photon radiation off the constituent light-flavour quark of the bottom meson at tree level. Furthermore, we explore the factorization properties of the subleading power correction from the effective SCET current $J^{(A2)}$ at ${\cal O} (α_s^0)$. The higher-twist contributions to the $B_{d, \, s} \to γγ$ helicity form factors from the two-particle and three-particle bottom-meson distribution amplitudes are evaluated up to the twist-six accuracy. In addition, the subleading power weak-annihilation contributions from both the current-current and QCD penguin operators are taken into account at the one-loop accuracy. We proceed to apply the operator-production-expansion-controlled dispersion relation for estimating the power-suppressed soft contributions to the double radiative $B_{d, \, s}$-meson decay form factors. Phenomenological explorations of the radiative $B_{d, \, s} \to γ\, γ$ decay observables in the presence of the neutral-meson mixing, including the CP-averaged branching fractions, the polarization fractions and the time-dependent CP asymmetries, are carried out subsequently with an emphasis on the numerical impacts of the newly computed ingredients together with the theory uncertainties from the shape parameters of the HQET bottom-meson distribution amplitudes.
