Insights on the cosmic origin of matter from proton stability

Abstract We investigate the phenomenology of a model [1] in which the proton is rendered absolutely stable by an IR mechanism that remains robust against unknown quantum gravity effects. A linear combination of baryon number and lepton flavors is gauged and spontaneously broken to a residual ℤ 9 discrete gauge symmetry enforcing a strict selection rule: Δ B = 0 (mod 3). Despite its minimal field content, the model successfully accounts for established empirical evidence of physics beyond the SM. High-scale symmetry breaking simultaneously provides a seesaw mechanism explaining the smallness of neutrino masses, minimal thermal leptogenesis, and a viable phenomenology of the majoron as dark matter. Any cosmic string-wall network remaining after inflation is unstable for numerous charge assignments. Lepton flavor non-universality, central to the construction, leads to predictive neutrino textures testable via oscillation experiments, neutrinoless double beta decay, and cosmology. The model motivates searches in X - and γ -ray lines, neutrino telescopes, and predicts CMB imprints.