Particle Structure from Codimension-Two Carrier Closure

The Standard Model accurately describes particle phenomena through continuous gauge fields, color, chirality, generations, and Yukawa couplings, but it does not derive these labels from a deeper structural principle. This paper proposes a carrier-resolution interpretation in which particle species are carrier-readable manifestations of a common loop-detectable codimension-two archetype defect. The carrier supplies Lorentzian propagation and globally available U(1) phase closure, while particle labels arise through holonomy, embedding, closure, and read-out conditions. The first persistent asymmetric resolution contains a lepton-like Z2-Lorentz branch and a hadron-supporting branch with confined Z3 closure. The Z2 branch accounts for spinorial and chiral read-out through twofold holonomy and Lorentz embedding, while the three observed fermion generations are interpreted as the three leading saturated projective embedding layers of the common Z2-Lorentz branch, not as consequences of the Z3 color-like layer. In this framework, Z3 supplies hadronic sectorality, and higher Zn refinements provide suppressed mass and response corrections rather than additional ordinary generations. The usual SU(3)C QCD description is retained as the effective after-read-out continuum gauge theory of color dynamics revealed by high-energy probes. The proposal does not replace QCD; instead, it interprets confined Z3 closure as a pre-read-out structural condition whose incomplete sectors are not carrier-readable as isolated hadrons. As a quantitative test, the neutron–proton magnetic-moment ratio is derived from an ideal Z3-complete baseline, a rule-generated closure-interface sequence, and a neutral-parent magnetic completion. The same-branch sequence reaches a sub-ppm residual and then saturates, so the remaining discrepancy is assigned to a neutral magnetic-completion seam rather than to deeper Zn terms. The resulting prediction is −0.684979364944, differing from the CODATA value of −0.68497935(16) by about 0.022 ppm, or 0.093 standard deviations. No coefficient is adjusted to fit the observed value. The result is presented as a sharp no-fit test of carrier-resolution and neutral-parent closure, not as a replacement for QCD or a complete theory of all baryon magnetic moments.