Relational Geometric Mechanics XI: Electroweak Unification — The Weinberg Angle and Neutrino Mass Structure from Descriptor Geometry

This is the eleventh paper in the Relational Geometric Mechanics (RGM) series. We derive the Weinberg angle sin²θW = 3/13 from first principles using only the descriptor geometry of Paper I and the force derivations of Papers II and V. No measurement input is required. The result — 0. 2308 against the measured Z-pole value of 0. 2312 — follows from making the descriptor space metric hAB explicit: the spinor structure S contributes exactly one topological generator to the 13-dimensional descriptor space, and the Weinberg angle is the ratio of the SU (2) footprint to the full descriptor geometry. The same framework yields the neutrino mass matrix structure: with qₑ = 0, the generation ring Hamiltonian produces an exact two-fold degeneracy, which is the geometric origin of large PMNS mixing angles.