AI 中文总结
该研究在非全纯模A₄框架内实现双 seesaw 机制，结合中微子振荡数据约束参数，其预测可在DUNE等实验检验，还能为热轻子生成提供可行方案。
AI 中文摘要
我们通过将标准模型扩展为包含三代右旋中微子（RHNs）、三代左手惰性中微子场以及一个A₄单态标量，在非全纯模A₄框架内实现了双 seesaw 机制。该模构造禁止了RHNs的裸马约拉纳质量项，并实现了双 seesaw 所需的层级结构，其中RHN质量通过较重的惰性中微子区诱导产生。对模参数空间的全面扫描得到了与当前中微子振荡数据一致的可行的正常序解。我们进一步研究了这些解在DUNE、T2HK和JUNO上的可检验性：DUNE和T2HK可对大气混合参数进行强探测并约束允许的模型空间，而JUNO则对太阳混合角和质量平方差提供互补的高精度灵敏度。与振荡兼容的点还确定了与热轻子生成相关的诱导RHN能谱和复杂汤川纹理。对于强 washout regime 中的一个代表性无风味基准，包含衰变和逆衰变的数值玻尔兹曼演化给出了Y_{ΔB}≃8.11×10⁻¹¹，接近观测到的重子不对称性。允许的参数空间还允许具有层级非共振RHN能谱的N₁主导双风味热轻子生成实现。我们的结果确立了非全纯模A₄双 seesaw 作为连接低能中微子现象学和热轻子生成的可预测框架，其振荡预测可在即将到来的高精度中微子实验中直接检验。
英文摘要
We realize the double seesaw mechanism within a non-holomorphic modular $A_4$ framework by extending the Standard Model with three generations of right-handed neutrinos (RHNs), three left-handed sterile neutrino fields, and an $A_4$-singlet scalar. The modular construction forbids a bare Majorana mass term for the RHNs and realizes the hierarchy required for the double seesaw, with RHN masses induced through the heavier sterile neutrino sector. A comprehensive scan of the modular parameter space yields viable normal ordering solutions consistent with current neutrino oscillation data. We further examine their testability at DUNE, T2HK, and JUNO. DUNE and T2HK strongly probe the atmospheric mixing parameters and constrain the allowed model space, while JUNO provides complementary precision sensitivity to the solar mixing angle and mass-squared splitting. The oscillation compatible points also determine the induced RHN spectrum and complex Yukawa textures relevant for thermal leptogenesis. For a representative unflavored benchmark in the strong-washout regime, numerical Boltzmann evolution including decays and inverse decays yields $Y_{ΔB}\simeq8.11\times10^{-11}$, close to the observed baryon asymmetry. The allowed parameter space also admits an $N_1$-dominated two-flavor thermal leptogenesis realization with a hierarchical, non-resonant RHN spectrum. Our results establish the non-holomorphic modular $A_4$ double seesaw as a predictive framework linking low-energy neutrino phenomenology and thermal leptogenesis, with oscillation predictions directly testable at forthcoming precision neutrino experiments.
Comments41 pages, 8 figures, 6 tables
