Physics 2.0 — The One Particle Theory: parameter-free predictions of the neutrino mass sum and the Koide relation from a single-primitive vacuum model

This work develops Physics 2. 0, a vacuum model in which the Standard Model's particle content and interactions are derived from a single primitive excitation organized on a vector-equilibrium lattice. Two results are stated as concrete, checkable claims. First, the Koide relation among the charged-lepton masses, Q = 2/3, is obtained as an exact theorem, equivalent to an equal-norm partition of a three-channel structure. Second, the same two dimensionless constants that fix the charged-lepton and hadron sectors fix the neutrino sector, yielding parameter-free forward predictions: a neutrino mass sum Σm_ν ≈ 0. 0727 eV, a discrete Dirac CP phase δCP = 240°, and an effective Majorana mass m_ββ ≈ 4. 39 meV. The same mechanism reproduces the full CKM matrix, including the quark CP phase, with the Cabibbo angle emerging as √ηᵣeturn. All headline numbers are reproduced from the model constants by the accompanying verification scripts; agreements are close-not-exact (ppm to sub-percent), the signature of forced derivations rather than fits. Open sectors, including the quark diagonal masses, are stated explicitly and not claimed. The neutrino mass sum sits just above the tightest current ΛCDM cosmological bound and within weaker dynamical-dark-energy bounds, making it falsifiable by incoming DESI/Euclid and DUNE data; a decision rule is committed in advance