Speaker
Description
The Standard Model successfully describes particle physics but cannot explain neutrino oscillations, the baryon asymmetry of the universe (BAU), and dark matter. The Aoki-Kanemura-Seto (AKS) model is a new physics model that can explain these three phenomena simultaneously at TeV scale testable by future experiments. However, in the original model published in 2009, the baryon number was not evaluated. In the present work [Enomoto, Kanemura, Taniguchi, JHEP06(2025)036], we introduced CP violation to the original AKS model for evaluating the baryon number and found a benchmark scenario to avoid the current constraint on the electron electric dipole moment while keeping a large enough CP-violating phase for electroweak baryogenesis. In this talk, we evaluate the baryon number in this model with some extension. Furthermore, we present benchmark points that can simultaneously explain neutrino masses, dark matter, and BAU, under various experimental and theoretical constraints. We also discuss prospects for testing the model at future experiments. We investigate gravitational-wave signals from the strong first-order electroweak phase transition and their detectability at future space-based observatories such as DECIGO. At colliders, the new particles predicted by the AKS model, including $S^\pm$ and the additional Higgs bosons $H_2$ and $H_3$, could be directly produced at the High-Luminosity LHC and future electron-positron colliders. Moreover, the sizable non-decoupling effects of the additional scalars required for a strong first-order electroweak phase transition can induce a measurable deviation in the Higgs triple coupling. Collider experiments therefore provide particularly important probes of this model through both direct searches and precision measurements of the Higgs sector.