Matter–Antimatter Asymmetry: Activation Framework, Constraints, and Model Comparison

We study an “Activation” (spontaneous-baryogenesis–like) operator ∂µϕ Jµ
B−L/MB inducing
µB = ˙ϕ/MB in a finite electroweak window. We unify the energy cap and derive rmax(MB, Tf)
with r ≡ ˙ϕ/(MBTf). A transparent derivation of C(T) is given and numerical values in the
window are tabulated. Diffusion/reaction matrices used in closure tests are stated. The
sphaleron freeze-out criterion Γsph/H = 1 is defined (with κ = 20) and linked to a consistent
Tf = 140 ± 10 GeV used across sections/figures. The connection to ∆L = 2 washout is
made explicit. Forecasts for ∆Neff, BAO phase and µ-distortion are provided with concrete
benchmarks. A reproducibility appendix lists all numerical inputs for scans.
Keywords: Baryogenesis, Spontaneous baryogenesis, Electroweak epoch, Leptogenesis,
Precision cosmology