The Neutrino as a Threshold State of Mass Generation: A Two-Level Crossing Model and Its Cosmological Test

At the earliest epoch of the universe, only energy is believed to have existed. Yet the process by which the mass of matter arose from it is not formulated as an independent piece of dynamics within current theory. The Higgs mechanism supplies the origin of the value of a mass; it does not describe the event in which a state acquires mass as an attribute. This paper poses this birth of mass as a testable piece of dynamics. Reading mass as the rotation of the rest-frame phase (the Compton frequency), an increment dm of mass acquires reality only as a phase shift, and interference reads nothing but differences: the structure by which neutrino oscillations measure only Δm² follows from this. Formulating the acquisition of mass as a driven two-level crossing (of Landau–Zener type) across the threshold m² = 0 yields a critical coupling gcrit 〜 ≈ 1 keV (v is the electroweak scale, MPl the Planck mass) separating completion of the transfer (ignition) from failure, and the observed fermion spectrum is sharply divided by this line: every charged fermion stands above it, even the lightest, the electron, by more than two orders of magnitude, while the neutrino alone stands four orders below. This paper therefore defines Δ, a state left standing at the edge of a threshold it failed to cross, and advances as a hypothesis the identification of Δ with the observed neutrino. If so, the cosmological measurement of the neutrino mass sum should fall below the floor Σmν ≥ 0.058 eV that oscillation data impose under standard cosmology. The tension that DESI DR2 has begun to show lies in this direction, and the determination of the mass ordering by JUNO together with the sensitivity of CMB-S4 will bring this prediction to a verdict within a few years. Keywords: neutrino mass, origin of mass, mass generation, Landau–Zener transition, Majorana neutrino, cosmological neutrino mass sum