Electroweak-Scale Majorana Neutrino Masses and Precision Phenomenology from Generalized Geometric Misalignment

In this study, we explore the phenomenological implications of the renormalizable geometric misalignment (RGM) framework, which we recently proposed to naturally generate Majorana neutrino masses at the electroweak scale. Built upon a small misalignment between the SU (2) gauge representation space and the chiral fields, this purely geometric approach achieves the sub-eV degenerate masses without relying on high-scale energies or severe fine-tuning. To accommodate full flavor mixing and CP-violating phases, we generalize the original RGM model by promoting the real, diagonal misalignment matrix Θ to a complex and off-diagonal form. Comparing the non-unitary predictions from this extended theory against the recent experimental data reveals that the precision constraints, specifically the 2025 MicroBooNE null result, the 2025 μ ⁺ → e ⁺ γ decay limit from MEG II and the 2024 ATLAS W -decay universality measurement, favor the highly suppressed natural regime (| Θ | ∼ 10 ^-7 ) over the high-mixing scenario (| Θ | ~ 10 ^-1 ). We further analyze the one-loop radiative corrections to the induced non-unitarity parameter and confirm that it is radiatively stable, consistent with 't Hooft's naturalness criterion. Finally, we discuss the implications of the intermediate regime (| Θ | ∼ 10 ^-3 –10 ^-2 ) wherein the geometry-induced non-unitary mixing effects can serve as practical targets for future precision tests.