Leptonic CP is Majorana-only: A Registered Prediction Addendum

Abstract

A dated prediction addendum to the neutrino-sector record (3 July and 6 July 2026), following the full pre-registration above: the numerical targets match the 1 July pre-registration, with the experimental content made explicit and a machine-readable JSON registration attached. The 6 July addendum upgrades the reason for the Dirac-CP null — it is not merely a real-PMNS assumption but follows from the same walk engine that makes the quark sector complex: rephasing-invariant Dirac CP needs transport through the colour register, and the colourless lepton register carries only rephasing-trivial phase. So leptonic CP is Majorana-only: the long-baseline Dirac phase is conserved (J_ℓ = 0, δ_CP ∈ {0, π}) while the CP-bearing object is a monitored R1/Majorana recovery-orientation record, showing up in neutrinoless double-beta decay and leptogenesis, not in oscillations. The same branch gives normal ordering with a fixed spectrum (m₁, m₂, m₃) = (0.79, 8.72, 50.16) meV and Σm_ν = 59.7 meV, and m_ββ = 1.76 meV (σ = +) or 3.07 meV (σ = −) — far below current and next-generation 0νββ reach. The branch is killed by high-significance intrinsic leptonic Dirac CP in normal ordering, an established inverted ordering, Σm_ν far above 60 meV, or a standard light-Majorana 0νββ interpretation with m_ββ ≳ 10 meV. Intentionally falsifiable: a nonzero Dirac phase would require a new complex PMNS response operator.

Keywords

How to cite

Elliman, D. (2026). Leptonic CP is Majorana-only: A Registered Prediction Addendum. Neuro-Symbolic Ltd technical report. https://doi.org/10.5281/zenodo.21251753

@techreport{elliman2026leptoniccpneutrinoprediction,
  author      = {Elliman, David},
  title       = {Leptonic CP is Majorana-only: A Registered Prediction Addendum},
  institution = {Neuro-Symbolic Ltd},
  year        = {2026},
  doi         = {10.5281/zenodo.21251753},
  url         = {https://neusym.ai/papers/leptonic_cp_neutrino_prediction/}
}