Neutron/Proton Freeze-Out · First Second
unseel.com · weak interactions · BBN · primordial helium
n / p ≈ 1 : 1
T > 10 MeV
Stage
Neutron (n)
Proton (p)
Weak rate Γ · Hubble H
Helium-4 nucleus
Unseel.com · Neutron-to-Proton Freeze-Out