New directions EXploring the Unknown beyond the Standard Model (NEXUS 2026)

Session

Parallel talks (2A)

12 Sept 2026, 16:20

Tsung-Dao Lee Institute/S5F-S500 - Lecture Room (Tsung-Dao Lee Institute)

21. Sphalerogenesis

Masanori Tanaka (Peking University)

12/09/2026, 16:20

Oral Presentation

In this talk, I discuss a new scenario that explains the baryon asymmetry of the Universe through a minimal extension of the Standard Model (SM). In this scenario, all three Sakharov conditions are simultaneously satisfied during the decoupling of CP-violating electroweak (EW) sphaleron processes. As the source of the CP asymmetry in the EW sphaleron process, we consider an effective theory in...

49. Bogoliubov approach for fermion production in Milne spacetime

Shota Nakagawa (Tsung-Dao Lee Institute, Shanghai Jiao Tong University)

12/09/2026, 16:40

Oral Presentation

First-order phase transitions in the early Universe are ubiquitous from the viewpoint of particle physics. Particle production during the nucleation and collision of bubbles has beed widely discussed. In this talk, we focus on fermion production induced by relativistic bubble collisions. The post-collision scalar-field dynamics in the planar approximation are described well in terms of Milne...

38. Bubble Wall Velocity in the Electroweak Phase Transition of the New Physics Model

Shihang Tang (Sun Yat-sen University)

12/09/2026, 17:00

Oral Presentation

The bubble wall velocity is a key parameter in cosmological first-order phase transitions, affecting both electroweak baryogenesis and gravitational-wave signals. However, it is often treated as an external input in phenomenological studies, while a self-consistent determination remains challenging. In this work, we investigate the bubble wall dynamics in the New Physics Model. The microscopic...

48. Particle Production via Rippled Bubble Walls

Yaoduo Wang (TDLI)

12/09/2026, 17:20

Oral Presentation

We investigate non-thermal particle production during first-order phase transitions in the presence of ultra-relativistic thick bubble walls with non-trivial internal structure. Extending the framework of bubble-expansion particle production, we consider bubble walls containing multiple ripples and study how such spatial modulations affect the production of heavy particles coupled to the order...