Geometric Stabilization of the Proton via Topological Protection in the Zhang Effective Metric

Grand unified theories predict baryon-number violation and proton decay, yet Super-Kamiokande has set a stringent lower bound τₚ>1.6×10³⁴ yr with no detected signal. We present a topological stabilization mechanism within the rotational-order geometric unification programme based on the Zhang Effective Metric. Baryon number is identified with the π₃(S³) winding charge of the internal S³ fibre configuration. While GUT X/Y gauge vertices still carry baryon-number-violating couplings, the quark–lepton transition must tunnel across a high-gradient topological barrier in the internal fibre. This barrier supplies an exponential suppression factor multiplying the standard GUT decay amplitude. With the geometric cutoff Λ_geo≈0.3 M_GUT linked to the fundamental scale shared across the series, the resulting proton lifetime becomes τₚ≳10⁴⁰ yr, consistent with present experimental limits. This scenario is distinguishable from symmetry-based baryon conservation and will be tested further by Hyper-Kamiokande.