Flavor and CP in supersymmetric extensions of the Standard Model

标准模型的超对称扩展中的风味和 CP

• 批准号: 249999962
• 负责人: Professor Dr. Andreas Weiler, since 8/2018
• 金额: --
• 依托单位: Department of Physics and Astronomy
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/249999962?language=en
• 关键词: Flavor; CP; supersymmetric; extensions; Standard

The main objective of this project is to address the question of the origin of flavor and CP violation in supersymmetric extensions of the Standard Model. Gaining new insights into these issues requires, in particular, a better understanding of the Kähler potential for several reasons. The Kähler potential mainly determines the soft mass pattern, which is eminent for the low-energy phenomenology of such theories. In particular, mixing among the scalar fields can induce flavor changing and CP violating processes among the matter particles. Moreover, the Kähler potential is not protected by the supersymmetric non-renormalization theorems and is corrected at the quantum level. This changes the field normalizations and determines the evolution of the couplings. In addition, the Kähler potential is less constrained by ordinary symmetries than the superpotential. Indeed, in a bottom-up approach it is difficult to control the size and existence of higher-order terms. This leads to non-negligible corrections to models with flavor symmetries. We will use three complementary strategies to solve these issues. In the first approach, we will analyze the problem bottom-up in supersymmetric gauge theories using, e.g., R symmetries, anomaly considerations and renormalization group invariants. Furthermore, we will compute the Kähler potential in higher-dimensional Grand Unified Theories. In these more constrained models, one has better control on the couplings in the Kähler potential because one can relate them to geometric properties like wave function overlaps. The third approach is to directly work out the Kähler potential in certain possibly realistic string compactifications like orbifolds. All these approaches should lead to mutually consistent results. Within all three approaches we will then try to obtain new information on the flavor structure and the breaking of the CP symmetry. A well-known bottom-up technique is to impose non-Abelian discrete flavor symmetries. However, most of the corresponding models do not make any predictions concerning CP violation. We will preclude scenarios where CP violation cannot be explained at all or only with unnatural fine tuning. This will not only be physically relevant but also be based on so far unexplored mathematical techniques related to the outer automorphism group of flavor symmetries, which is known to be related to the CP symmetry. A study of higher-dimensional Grand Unified Theories and string theories, in which the origin of discrete flavor symmetries is well understood since they originate from additional compact extra dimensions, will enable us to identify phenomenologically viable scenarios.

这个项目的主要目标是解决在标准模型的超对称扩展中味道的起源和CP破坏的问题。要获得对这些问题的新见解，尤其需要更好地理解卡勒的潜力，这有几个原因。Kähler势主要决定软质量模式，这是此类理论的低能现象学的突出特点。特别是，标量场之间的混合可以诱导物质粒子之间的味道变化和CP破坏过程。此外，Kähler势不受超对称非重整化定理的保护，而是在量子水平上得到修正。这改变了场的规格化，并决定了耦合的演化。此外，与超势相比，Kähler势受普通对称性的限制较少。事实上，在自下而上的方法中，很难控制高阶项的大小和存在。这导致了对具有味道对称性的模型的不可忽略的修正。我们将使用三个相辅相成的战略来解决这些问题。在第一种方法中，我们将自下而上地分析超对称规范理论中的问题，例如，使用R对称、反常考虑和重整化群不变量。此外，我们还将计算高维大统一理论中的Kähler势。在这些更受约束的模型中，人们可以更好地控制Kähler势中的耦合，因为人们可以将它们与波函数重叠等几何性质联系起来。第三种方法是直接计算某些可能现实的弦紧化的Kähler势。所有这些办法都应该产生相互一致的结果。在所有这三种方法中，我们将尝试获得关于风味结构和CP对称性破坏的新信息。一种众所周知的自下而上的技术是施加非阿贝尔离散风味对称性。然而，大多数相应的模型都没有对CP违规做出任何预测。我们将排除根本无法解释CP违规的情况，或者只能通过不自然的微调。这不仅与物理相关，而且还基于迄今尚未探索的与气味对称的外自同构群相关的数学技术，已知的外自同构群与CP对称有关。对高维的大统一理论和弦理论的研究将使我们能够识别在现象上可行的情景。在这些理论中，离散味道对称性的起源被很好地理解，因为它们来自额外的紧凑额外维度。