AI 中文总结
提出基于$A_{4}$模对称的Dirac逆跷跷板模型，统一解释中微子质量与自相互作用暗物质，其非弹性散射可解释LZ 248 keV事件，并预言引力波信号。
AI 中文摘要
我们提出了一种新颖的框架，该框架同时解决了Dirac中微子质量的起源和自相互作用暗物质（SIDM）的本质问题。该模型基于$A_{4}$模对称性，以确保中微子的Dirac性质以及暗物质的稳定性。中微子扇区实现了Dirac逆跷跷板机制，其中中微子质量的小尺寸由单态标量$\phi$的真空期望值（VEV）控制。这个相同的标量与一个矢量样费米子暗物质候选者耦合，诱导出微小的Majorana质量劈裂，使暗物质成为伪Dirac型且非弹性的。至关重要的是，该标量还充当暗物质自相互作用的轻介质，可能解决冷暗物质的小尺度结构问题。鉴于最近LUX-ZEPLIN（LZ）暗物质直接探测实验观测到的248 keV核反冲事件LZ230616，我们证明了我们的非弹性SIDM参数空间通过吸热散射运动学自然地容纳了这一信号。此外，这种非弹性所需的暗宇称自发破缺产生了一个宇宙学畴壁网络。我们表明，为了安全湮灭这些畴壁所需的显式对称性破缺会产生随机引力波背景。非全纯模对称性减少了自由参数，将中微子观测量、暗物质现象学、$\Delta N_{\rm eff}$和引力波特征关联起来。
英文摘要
We propose a novel framework that simultaneously addresses the origin of Dirac neutrino masses and the nature of self-interacting dark matter (SIDM). The model is based on an $A_{4}$ modular symmetry to ensure the Diracness of neutrinos as well as the stability of the DM. The neutrino sector realizes a Dirac Inverse Seesaw mechanism where the smallness of the neutrino mass is governed by the vacuum expectation value (VEV) of a singlet scalar $ϕ$. This same scalar couples to a vector-like fermion DM candidate, inducing a tiny Majorana mass splitting that renders the DM pseudo-Dirac and inelastic. Crucially, the scalar also acts as a light mediator for DM self-interactions, potentially solving the small-scale structure problems of Cold DM. In light of the recent 248 keV nuclear-recoil event, LZ230616, observed by LUX-ZEPLIN (LZ) DM direct detection experiment, we demonstrate that our inelastic SIDM parameter space naturally accommodates this signal via endothermic scattering kinematics. Furthermore, the spontaneous breaking of the dark parity required for this inelasticity produces a network of cosmological domain walls. We show that the explicit symmetry breaking needed to safely annihilate these walls generates a stochastic gravitational wave background. The non-holomorphic modular symmetry reduces the free parameters, correlating neutrino observables, addressing DM phenomenology, $ΔN_{\rm eff}$, and gravitational-wave signatures.
Comments35+12 pages, 12 captioned figure, 4 tables
