In a class of gauged $U(1)$ extended Standard Models (SMs), the breaking of the $U(1)$ symmetry is not only a source for Majorana masses of right-handed (RH) neutrinos crucial for the seesaw mechanism, but also a source of stochastic gravitational wave (GW) background. Such $U(1)$ extended models are well-motivated from the viewpoint of grand unification. In this paper, we discuss a successful ultraviolet completion of a $U(1)$ extended SM by an $SO(10)$ grand unified model through an intermediate step of $SU(5) \times U(1)$ unification. With a parameter set that is compatible with the $SO(10)$ grand unification, we find that a first-order phase transition associated with the $U(1)$ symmetry breaking can be strong enough to generate GWs with a detectable size of amplitude. We also find that the resultant GW amplitude reduces and its peak frequency becomes higher as the RH neutrino masses increase.

中文翻译：

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SO(10) 大统一中额外的 U(1) 破裂产生的引力波

在一类测量的 $U(1)$ 扩展标准模型 (SM) 中，$U(1)$ 对称性的破坏不仅是马约拉纳质量的右手 (RH) 中微子的来源，这对于跷跷板机制至关重要，也是随机引力波（GW）背景的来源。从大统一的角度来看，这种 $U(1)$ 扩展模型是有充分动机的。在本文中，我们通过 $SU(5)\times U(1)$ 统一的中间步骤，通过 $SO(10)$ 大统一模型讨论了 $U(1)$ 扩展 SM 的成功紫外完成。使用与 $SO(10)$ 大统一兼容的参数集，我们发现与 $U(1)$ 对称性破坏相关的一阶相变可以足够强，以生成可检测大小为振幅。