In a bid to simultaneous explanation of dark matter (DM) and tiny but non-zero masses of left-handed neutrinos, we propose a minimal extension of the Standard Model (SM) by a vector-like fermion doublet and three right handed (RH) singlet neutrinos. The DM arises as a mixture of the neutral component of the fermion doublet and one of the RH neutrinos, both assumed to be odd under an additional 𝒵₂ symmetry. As a result, the DM emerges to be a dominantly Majorana particle and escapes from Z-mediated direct search constraints to mark a significant difference from singlet-doublet Dirac DM. The other two 𝒵₂ even heavy RH neutrinos give rise masses and mixing of light neutrinos via Type-I Seesaw mechanism. The particle content automatically allows us to extend the model by a gauged U(1)_B-L symmetry, which is anomaly free and brings an additional portal between DM and SM particles. Relic density and direct search allowed parameter space for both the cases are investigated through detailed numerical scan, while collider search strategies are alsoindicated.

为了同时解释暗物质（DM）和左手中微子的微小但非零质量，我们建议通过矢量型费米子二重态和三个右手（RH）最小扩展标准模型（SM）。 ）单线态中微子。的DM产生作为费米子双峰的中性组分和RH中微子的一个，两个假定的附加𝒵下为奇数的混合物₂的对称性。结果，DM成为主要的Majorana粒子，并且摆脱了Z介导的直接搜索限制，从而标志着与单重-双重Dirac DM的显着差异。另外两个𝒵 ₂甚至重RH中微子引起群众和通过I型翘板机构光中微子混合。粒子含量自动允许我们将模型扩展到指定的U（1）_BL对称性无异常，并在DM和SM粒子之间带来了另一个入口。通过详细的数值扫描研究了这两种情况的文物密度和直接搜索允许的参数空间，同时还指出了对撞机搜索策略。