论文标题
阈值变量在$ t \ bar {t} h $生产过程中的软光射中的作用
The role of the threshold variable in soft-gluon resummation of the $t\bar{t}h$ production process
论文作者
论文摘要
我们研究阈值变量在软脱光阈值重新召集中的作用。我们专注于重新召集的总横截面，最终状态不变的质量分布以及Higgs玻色子的横向摩肌分布，与在13 TEV处运行的大型强子对撞机的顶部顶部夸克对生产时。我们表明，阈值变量的不同选择会导致在近代领导力下的差异，即通过阈值变量的一个幂降低的贡献。这些贡献在数值上是显而易见的，尽管它们对重新召集的可观察结果的影响在于这些可观察到的不确定性范围内。在结合了几个中心尺度选择后获得的平均中心结果，对于阈值变量的不同选择，非常吻合。但是，不同的阈值选择确实会影响所得的尺度不确定性。为了计算我们的结果，我们引入了一种新型的数值方法，我们称之为变形方法，该方法有助于稳定逆变蛋白转化的情况，而partononic横截面的分析梅林变换是未知的。我们表明，这种方法导致少10倍的功能评估，同时与标准方法相比，数值精度为4-5。
We study the role of the threshold variable in soft-gluon threshold resummation. We focus on the computation of the resummed total cross section, the final-state invariant-mass distribution, and transverse-momentum distribution of the Higgs boson when produced in association with a top-anti-top quark pair for the Large Hadron Collider operating at 13 TeV. We show that different choices for the threshold variable result in differences at next-to-leading power, i.e. contributions that are down by one power of the threshold variable. These contributions are noticeable numerically, although their effect on the resummed observables lies within the scale uncertainty of those observables. The average central results, obtained after combining several central-scale choices, agree remarkably well for different choices of the threshold variable. However, different threshold choices do effect the resulting scale uncertainty. To compute our results, we introduce a novel numerical method that we call the deformation method, which aids the stabilization of the inverse Mellin transform in cases where the analytical Mellin transform of the partonic cross section is unknown. We show that this method leads to a factor of 10 less function evaluations, while gaining a factor of 4-5 in numerical precision when compared to the standard method.
