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。这种新粒子现在成为理论和实验上深入研究的中心对象，以便精确确定其特性。 特别是，了解这个希格斯玻色子是否只是标准模型（SM）希格斯玻色子或者它是否是更一般理论的一部分是很有趣的。为了回答这个问题，精确的理论预测是必要的，无论是在 SM 内还是在 SM 的扩展内。这些精确的理论预测在这个项目中得到了解决。环引起的过程在希格斯物理学的背景下发挥着特殊的关键作用。由于希格斯玻色子仅与大质量粒子耦合，因此涉及初始或最终状态的无质量粒子（如胶子或光子）的希格斯玻色子产生和衰变过程通过大粒子环进行。这些环路诱发的过程一方面很重要，因为它们对大型强子对撞机上希格斯玻色子的发现做出了重大贡献，另一方面它们对 SM 之外的新物理很敏感。SM 希格斯扇区最简单的扩展之一是在 SM 场内容中添加额外的自旋零规范单线态。该模型具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仍然悬而未决的问题，这些问题在 SM 中仍未得到解答，例如暗物质的本质问题或宇宙物质-反物质不对称性的起源问题。 在该项目中，将分析微扰理论中的电弱校正对环路诱发过程的影响。由于循环引发过程的前序过程已经处于单循环级别，因此下一前序校正的计算在这里已经涉及具有挑战性的二循环图的计算。