Precision calculations for loop-induced Higgs-boson production and decay processes

环路诱导希格斯玻色子产生和衰变过程的精确计算

• 批准号: 436076086
• 负责人: Dr. Christian Sturm
• 金额: --
• 依托单位: Institut für Theoretische Physik und Astrophysik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2020
• 资助国家: 德国
• 起止时间: 2019-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/436076086?language=en
• 关键词: Precision; calculations; loop; induced; Higgs

One of the most important achievements of particle physics in the last decade was the discovery of a Higgs boson at the Large Hadron Collider(LHC) experiments. This new particle is now central object of intense investigations, both in theory and experiment, in order to precisely determine its properties. In particular, it is interesting to understand whether this Higgs boson is just the Standard Model(SM) Higgs boson or whether it is part of a more general theory. In order to give answers to this question precise theory predictions are necessary, both within the SM as well as within extensions of the SM. These precise theory predictions are addressed in this project.Loop-induced processes play a special key role in the context of Higgs physics. Since the Higgs boson only couples to massive particles, Higgs-boson production and decay processes which involve massless particles in the initial or final state, like gluons or photons, proceed via a massive particle loop. These loop-induced processes are important on the one hand since they contributed substantially to the discovery of a Higgs-boson at the LHC, on the other hand they are sensitive to new physics beyond the SM.One of the simplest extensions of the Higgs sector of the SM is the one with an extra spin-zero gauge singlet added to the SM fieldcontent. This model has a rich collider phenomenology which can be tested at the LHC. This model can also give answers to still open questions, which remain unanswered within the SM, like for example, the question of the nature of dark matter or the question of the origin of the matter-antimatter asymmetry of the Universe. Within this project the impact of electroweak correction in perturbation theory to loop-induced processes shall be analyzed. Since the leading-order process for loop-induced processes is already at the one-loop level, the computation of next-to-leading order corrections involves here already the computation of challenging two-loop diagrams.

过去十年中粒子物理学最重要的成就之一是在大型强子对撞机(LHC)实验中发现了希格斯玻色子。为了准确地确定它的性质，这种新粒子现在是理论和实验上密集研究的中心对象。特别是，理解这个希格斯玻色子是标准模型(SM)希格斯玻色子，还是更一般理论的一部分，这是很有趣的。为了给出这个问题的答案，精确的理论预测是必要的，无论是在SM内部还是在SM的扩展范围内。这些精确的理论预测将在这个项目中得到解决。在希格斯物理的背景下，环诱导过程扮演着特殊的关键角色。由于希格斯玻色子只与大质量粒子耦合，希格斯-玻色子的产生和衰变过程涉及处于初始或最终状态的无质量粒子，如胶子或光子，通过质量粒子循环进行。这些环诱导的过程一方面是重要的，因为它们在LHC发现了希格斯玻色子，另一方面，它们对SM以外的新物理很敏感。SM的Higgs扇区最简单的扩展之一是在SM场内容中增加了一个额外的自旋零规范单态。这个模型有丰富的对撞机现象学，可以在大型强子对撞机上进行测试。这个模型还可以回答SM中仍未回答的悬而未决的问题，例如，暗物质的性质问题或物质-反物质不对称的起源问题。在本项目中，应分析微扰理论中的弱电修正对回路感应过程的影响。由于循环诱导过程的先导顺序过程已经处于单环水平，因此在这里计算次要的前导顺序修正已经涉及到具有挑战性的双环图的计算。