AI 中文总结
研究无显式味对称的味模型“味对称的沼泽地”，通过重新审视最小型II跷跷板模型及给出两个标准模型味参数可算但对称隐含的例子展示其预测力，还探讨了与轻新粒子的关系及对轴子味违反相互作用的计算分析。
AI 中文摘要
在本论文中，我们展示了无显式味对称的味模型的预测能力，即“味对称的沼泽地”。首先，我们重新审视最小型II跷跷板模型，它通过一个TeV尺度的三重态标量场扩展标准模型。我们发现中微子质量矩阵的某些味纹理能抑制严格受限的μ→e跃迁率，并允许5 - 6 TeV的有效截止尺度，即便相关味对称都被强烈破坏。接着，我们给出两个例子，其中一些标准模型味参数可计算，但潜在对称仍隐含。一是在最简化的SO(10)理论中，虽夸克 - 轻子对称在低能不显现，但当标量区的轻子夸克处于TeV尺度时，能正确预测b - τ质量比。二是我们在标准模型（含三个右手中微子）中识别出一类新的无反常手征对称，即增强的B - L，在此框架下中微子质量非自由参数，而是通过动力学对称破缺效应即中微子凝聚产生。此外，味对称的沼泽地可能涉及轻的新粒子，特别是有味轴子。作为初步研究，我们计算了最小轴子模型中轴子味违反相互作用被忽视的两圈贡献，并分析其对解释近期 Belle II 上的一个过剩的影响。
英文摘要
In this thesis, we demonstrate the predictive power of the flavour models without explicit flavour symmetries, which we call the `swampland of flavour symmetries'. Firstly, we revisit the minimal type II seesaw model, which extends the Standard Model (SM) with a TeV-scale triplet scalar field. We find that certain flavour textures of the neutrino mass matrix can suppress the tightly constrained $μ\to e$ transition rates and allow a $5-6$ TeV effective cut-off scale, even when the relevant flavour symmetries are all strongly broken. Next, we show two examples in which some SM flavour parameters are calculable, but the underlying symmetries remain implicit. (i) In the most minimal $SO(10)$ theory, although the quark-lepton symmetry does not manifest at low energies, we find that the $b-τ$ mass ratio can be correctly predicted when the leptoquarks contained in the scalar sector lie at TeV scale, as motivated by the long-standing $B$ anomalies. (ii) We identify a new class of anomaly-free chiral symmetries in the SM (including three right-handed neutrinos), referred to as enhanced $B-L$, under which all neutrinos are massless. In this framework, the neutrino masses are not free parameters but arise solely through the dynamical symmetry breaking effects, known as neutrino condensate. Furthermore, we note that the swampland of flavour symmetries could also involve light new particles, in particular the flavourful axions. As a preliminary study, we calculate an overlooked two-loop contribution to the axion flavour violating interactions in a minimal axion model, and analyze its impact on explaining a recent excess at Belle II.
CommentsPh.D. Thesis, 150 pages
