Geometric Origin of the Neutrino: Whole-Rotation Dominance, Chirality from Unidirectional B⁵ Rotation, and a Quantitative Mass Prediction

The electron neutrino is the lightest known massive fermion, yet the Standard Model provides no structural explanation for its properties — zero charge, spin-1/2, exclusively left-handed chirality, and mass at least 10⁶ times smaller than the electron — or for why it pairs with the electron in a weak isospin doublet. This paper — PP-06 in the META Physics preprint series — derives the geometric ORIGIN of the neutrino from the rotation hierarchy of the uniformly rotating four-dimensional ball B⁴ (R) and its five-dimensional mother body B⁵ (R). Six results are established with zero free parameters. (I) The neutrino is identified as the R₅-dominated state (whole-rotation component) of the coalescent zero-dimensional point on S³ (R), in contrast to the electron which is the R₄-dominated state (self-rotation component). (II) Electric charge Q = 0: the isoclinic whole-rotation produces no differential Hopf fiber winding (winding number n = 0). (III) Left-handed chirality only: a new ground condition GC-B⁵-Uni — the rotation of B⁵ (R) is unidirectional, an ontological consequence of B⁵ being the supreme substance with no higher-dimensional reference frame — fixes the chirality to a single handedness. This is the geometric ORIGIN of the V−A structure of the weak interaction. (IV) Quantitative mass prediction: the inverse-structure calculation yields mν = mₑ × (α/√e) ³ ≈ 0. 044 eV, with neutrino stacking number Nν = α⁻¹⁶/e ≈ 5. 7 × 10³³. This prediction satisfies the KATRIN direct upper limit (< 0. 45 eV) and is experimentally testable by next-generation facilities (Project 8, LEGEND-200, DESI, CMB-S4). (V) The weak isospin doublet (νₑ, e⁻) L is identified with the (R₅, R₄) superposition at each zero-dimensional point — a structural necessity, not an imposed symmetry. (VI) The neutrino is predicted to be a Majorana particle: since n = 0 for both neutrino and antineutrino, there is no topological distinction between them. The mass ratio m_ν/mₑ ~ 10⁻⁷ arises from two independent mechanisms: (a) the absence of topological confinement (no Hopf fiber winding, n = 0), and (b) the small energy scale Ω₅/Ω̄ = α/√e ≈ 0. 0044 (0. 44%). Three complementary plane-pairings of the whole-rotation provide a candidate structure for neutrino oscillation (speculative direction). This is the only paper in the META Physics preprint series with an experimentally verifiable quantitative prediction (m_ν ≈ 0. 044 eV) testable within the current decade. Mathematical formalization and documentation: Claude (Anthropic, Claude Opus 4. 6). The core insights, physical intuitions, and axiom system originate from the author's 30 years of independent research.