AI 中文总结
该研究提出T4-3-i拓扑的完整场论实现，构建含狄拉克费米子等的T4-3-i-B1模型，解释马约拉纳中微子质量，费米子与标量暗物质均可行，共湮灭对遗迹丰度关键。
AI 中文摘要
我们提出了有限单圈T4-3-i拓扑的首个完整场论实现，用于马约拉纳中微子质量的产生。此处T4-3-i表示外希格斯对与两个外部轻子对相连的外 Weinberg 算符的单圈实现。若该费米子为马约拉纳单态或三重态，相同相互作用会分别产生树级的I型或III型 seesaw 贡献，因此该圈并非中微子质量的主要来源。通过将中介体取为狄拉克费米子N，将轻子数破缺置于圈内的独立马约拉纳费米子ψ中，并引入精确的Z₂对称性（使新标量保持惰性并稳定最轻的奇异性态），可消除该低阶贡献。我们对允许的电弱荷分配进行分类，并研究最小的单态-二重态实现，记为T4-3-i-B1，其包含1个狄拉克费米子、1个马约拉纳费米子、1个惰性标量二重态和1个惰性标量单态。所得的秩-二中微子质量矩阵预言存在1个无质量中微子。我们将正常和倒置的中微子质量序与中微子振荡及宇宙学数据、带电轻子味违反（包括μ-e转换）、电弱精确可观测量、h→γγ、理论一致性条件、遗迹丰度及直接探测限进行对比。费米子和标量暗物质均可行：费米子候选仅具有圈诱导的希格斯耦合，因此自旋无关散射率被强烈抑制；而标量候选通过树级希格斯门户耦合，可位于中微子本底之上且仍符合当前限制。两种情况下，与惰性标量的共湮灭对重现观测到的遗迹丰度均至关重要。
英文摘要
We present the first complete field-theoretic realization of the finite one-loop T4-3-i topology for Majorana neutrino mass. Here, T4-3-i denotes a one-loop realization of the Weinberg operator in which a fermion links the two external lepton--Higgs pairs. If this fermion is a Majorana singlet or triplet, the same interactions generate a tree-level type-I or type-III seesaw contribution, respectively, so that the loop is not the leading source of neutrino mass. This lower-order contribution is removed by taking the mediator to be a Dirac fermion $N$, placing lepton-number violation in a separate Majorana fermion $ψ$ inside the loop, and imposing an exact $Z_2$ symmetry that keeps the new scalars inert and stabilizes the lightest odd state. We classify the allowed electroweak charge assignments and study the minimal singlet-doublet realization, denoted T4-3-i-B1, which contains one Dirac fermion, one Majorana fermion, an inert scalar doublet, and an inert scalar singlet. The resulting rank-two neutrino mass matrix predicts one massless neutrino. We confront both normal and inverted neutrino-mass orderings with neutrino-oscillation and cosmological data, charged-lepton flavor violation, including $μ-e$ conversion, electroweak precision observables, $h\toγγ$, theoretical consistency conditions, the relic abundance, and direct-detection limits. Both fermionic and scalar dark matter are viable. The fermionic candidate has only a loop-induced Higgs coupling and consequently a strongly suppressed spin-independent scattering rate, whereas the scalar candidate couples through a tree-level Higgs portal and can lie above the neutrino floor while remaining compatible with current limits. In both cases, coannihilation with inert scalars is essential for reproducing the observed relic abundance.
Comments27 pages, 14 figures
