标题： 高质量复合Pati-Salam轴子 显示英文标题

标题： A High-Quality Composite Pati-Salam Axion

摘要： 我们提出了一种复合QCD轴子模型，在这个模型中，Peccei-Quinn（PQ）对称性作为一个高质量的意外对称性出现。轴子势仅被八个费米子、维度12的算符所修改，如果这些算符存在于普朗克尺度，那么它们允许通过误align机制产生轴子暗物质的同时解决强CP问题。该模型是一种带有十个味的$\text{SU}(N_c)$规范理论，在其中Pati-Salam统一子群$\text{SO}(6)\times \text{SO}(4) \subset \text{SU}(10)_L$和$\text{Sp}(10)\subset \text{SU}(10)_R$被弱规范。动力学破坏了$\text{SU}(10)_L\times \text{SU}(10)_R \rightarrow \text{SU}(10)_V$并对弱规范群进行破缺，形成$\text{U}(3)\times \text{U}(2) \supset \text{SU}(3)_c \times \text{SU}(2)_L \times \text{U}(1)_Y$，其中QCD轴子被识别为Nambu-Goldstone玻色子之一。这种轴子与光子有相对较大的耦合，而剩余的$\bar{\theta}_{\rm eff}$可能刚刚低于中子电偶极矩的当前限制。如果维度12的算符存在于大统一理论（GUT）尺度附近，它们可以使畴壁网络衰变，从而即使在后膨胀场景下也允许轴子暗物质的存在。 显示英文摘要

摘要： We present a composite QCD axion model where the Peccei--Quinn (PQ) symmetry emerges as a high-quality, accidental symmetry. The axion potential is only modified by eight-fermion, dimension 12 operators, which if present at the Planck scale, allow for axion dark matter from misalignment while solving the strong CP problem. The model is an $\text{SU}(N_c)$ gauge theory with ten flavors where the Pati--Salam unified subgroup $\text{SO}(6)\times \text{SO}(4) \subset \text{SU}(10)_L$ and $\text{Sp}(10)\subset \text{SU}(10)_R$ are weakly gauged. The dynamics breaks $\text{SU}(10)_L\times \text{SU}(10)_R \rightarrow \text{SU}(10)_V$ and the weakly-gauged groups to $\text{U}(3)\times \text{U}(2) \supset \text{SU}(3)_c \times \text{SU}(2)_L \times \text{U}(1)_Y$, with the QCD axion identified as one of the Nambu-Goldstone bosons. This axion has a relatively large coupling to photons while a residual $\bar{\theta}_{\rm eff}$ may be just below the current limit on the neutron electric dipole moment. If the dimension 12 operators are present near the GUT scale, they can cause domain wall networks to decay, allowing for axion dark matter even for the post-inflationary scenario.