强子对撞机上Higgs联合产生过程的高阶QCD效应

In the Standard Model, the Higgs mechanism plays key role to electroweak symmetry breaking and mass origin of elementary particles. Since the discovery of Higgs at the LHC in 2012, the investigation of Higgs properties including Higgs self-interaction and Higgs gauge couplings has become one of the most important missions at LHC. Therefore, the accurate theoretical predictions including high order QCD effect for the Higgs associate productions are critical for the Higgs physics research in the future. However, the most advanced investigations of the high order QCD effect in Higgs associate production are all contaminated by certain approximation scheme to simplify the multi-loop calculation. In this project, without any unnecessary approximation we will investigate the complete high order QCD effects including next-to-leading order (NLO) and next-to-next-to-leading order (NNLO) effects for the Higgs pair production, the associate Higgs and jet production and the associate Higgs and gauge boson production induced by gluon fusion at the hadron colliders. Furthermore, we will investigate the theoretical uncertainties of our theoretical predictions including complete high order QCD effect. And we will be able to precisely understand the influence of the high order QCD effects on the measurement of Higgs properties, e.g. Higgs self-coupling and Higgs gauge coupling, at the LHC and future hadron colliders.

在标准模型中，Higgs机制负责着电弱对称性破缺并赋予了基本粒子质量。自2012年Higgs玻色子在LHC上被发现之后，对Higgs粒子的自耦合与规范耦合等重要物理性质的测量研究便成为了LHC未来最为重要的任务之一。因此，对于Higgs联合产生过程的精确理论预言是未来Higgs物理性质研究的关键所在。然而，目前最好的对于Higgs联合产生过程的高阶QCD效应的研究均采用了一定的近似条件以降低多圈图计算的复杂度。在本项目中，我们将针对强子对撞机上由胶子融合诱导的Higgs对产生、Higgs与喷柱联合产生以及Higgs与规范玻色子联合产生过程，计算并分析完整次领头阶与次次领头阶QCD效应。进而，我们可以精确可靠地分析高阶QCD修正效应对理论预言不确定度的影响，以及其对LHC和未来强子对撞机上Higgs自耦合常数与规范耦合常数等物理性质测量的影响。

在现代物理研究的高能量前沿中，高能对撞机上产生希格斯玻色子并对其基本物理性质进行准确研究是目前最为重要的科学工作之一。在本项目的研究工作中，我们成功得到了希格斯工厂中希格斯玻色子和Z玻色子联合产生过程的电弱和QCD混合修正效应，我们的结果是希格斯玻色子产生过程中精度最高的理论预言。此外，利用机器学习的卷积神经网络方法，我们改善了希格斯工厂中希格斯玻色子与胶子有效耦合的测量，为未来实验中以更高精度抽取胶子的有效Yukawa耦合提供了新的高效方法。另外，为了其他重要物理散射过程的高阶辐射效应的研究工作，我们开创性地提出了适用范围更广效率更高的新的振幅约化方法。