Lepton and Quark Flavour Structures

16 Oct 2024, 11:00 → 19 Oct 2024, 13:00 Asia/Shanghai

The Workshop on Lepton and Quark Flavour Structures will be hosted in Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences (HIAS-UCAS) on October 16-19, 2024.

The workshop will focus on fermion masses and mixing and the potential origins behind. It has been confirmed that all fermions, including quarks and leptons perhaps except the lightest neutrino, have masses and they mix in the charged-current interaction. A series of experiments have been operated / proposed on precision measurements on the mixing parameters. In particular, Jiangmen Underground Neutrino Observatory (JUNO) will take data in a few months. On the other hand, the origin of flavor mixing is still a mystery. We have not convinced us why the lepton mixing is so different from the quark mixing, and what is the mechanism behind them. We will address these questions in this workshop. 

Basic informations of the workshop

1) Time: Oct 16-19, 2024, including arrival and departure dates

2) Location: Meeting Room on 2rd floor, Building 3, Yunyi Campus, HIAS-UCAS

                    杭高院云艺园区3号楼2楼会议室

3) Registration fee: 1500 RMB / faculty or postdoc, 1000 RMB / student.

4) Accommodation: It is convenient to book a hotel nearby. If you prefer to have an accommodation in the campus, please specify it during your registration in the indico system.

Thursday, 17 October

1 Conceptual design report of muonium to antimuonium conversion experiment (MACE)

The spontaneous conversion of muonium to antimuonium is one of the interesting charged lepton flavor violation phenomena, offering a sensitive probe of potential new physics and serving as a tool to constrain the parameter space beyond the Standard Model. Utilizing a high-intensity muon beam, a Michel electron magnetic spectrometer and a positron transport solenoid together with a positron detection system, MACE aims to discover or constrain this rare process at the conversion probability beyond the level of $10^{-13}$. This talk will release the conceptual design report for MACE.

Speaker: Jian Tang (Sun Yat-Sen University)

20241017_正反缪子素转化实验概念设计报告_by_唐健.pdf

2 Revealing the Origin of Neutrino Masses through Displaced Shower Searches in the CMS Muon System

We study the potential to probe the origin of neutrino masses, by searching for long-lived right-handed neutrinos (RHNs) $N$ in the $B-L$ model. Despite the small active-sterile mixing $|V_{\ell N}|^2$, RHNs are produced abundantly via SM and exotic Higgs production, as long as the Higgs mixing is sufficiently large. We reinterpret a search for displaced showers in the CMS muon system and we find that it is sensitive to parameter space at and below the seesaw floor, $|V_{\ell N}|^2 \approx 10^{-12}$ ($\ell = e$, $\tau$) for $m_N \approx 40$ GeV. With existing data constraining such a well-motivated scenario of neutrino mass generation, we determine the projected sensitivity at the HL-LHC, motivating dedicated searches for long-lived RHNs with decay lengths $\approx 10$ m.

Speaker: Wei（刘威） Liu (Nanjing University of Science and Technology（南京理工）)

talk-LLP.pdf

talk-LLP.pptx

10:00 集体合影 茶歇

3 Probing neutrino-DM interactions at JUNO

Speaker: 永超 张

4 Non-Abelian domain walls: connecting flavour symmetry to gravitational waves

Speaker: 博文 付

11:30 午餐

5 自由讨论

18:00 晚餐

Friday, 18 October

6 An SU(8) theory of the SM quarks and leptons

We propose an SU(8) theory to originate the observed SM quark/lepton mass hierarchies and the CKM mixing pattern with the non-universal embedding structure, as well as the gravitational effect.

Speaker: 宁 陈 (Nankai University)

SU8_talk.pdf

7 Calculable neutrino Dirac mass matrix in the minimal left-right symmetric model

Based on the paper: arXiv:2404.16740 (PRD). In the context of minimal left-right symmetric model, where parity is taken as the left-right symmetry, we propose a general parametrization of the right-handed neutrino mixing matrix and construct the heavy neutrino mass matrix that maintains the Hermiticity of neutrino Dirac mass matrix. We further apply it to calculate the strong CP parameter from the leptonic CP violation at the one-loop level, which inversely constrains the heaviest sterile neutrino mass at the TeV scale.

Speaker: Prof. Gang (刚) Li (李) (Sun Yat-Sen University)

2024_HIAS_LRSM_MD_Gang_Li.pdf

10:00 茶歇

8 Some pheno aspects of modular symmetries

Speaker: 也铃 周

9 Discussion on modular symmetries

11:30 午餐

10 Fermion masses and mixing in SO(10) GUT with a universal two-zero texture

Speaker: 高祥 方

11 Gravitational waves from phase transition during inflation（暴涨时期的相变引力波——开题报告）

Speaker: 禧贺 胡

18:00 晚宴