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Stability of the proton and neutron

Decay of the Proton

A free proton (one outside a nucleus) has long been considered to be a stable particle, but recent developments of grand unification models have suggested that it might decay with a half-life of about 1031 years. (WOW! 10,000,000,000,000,000,000,000,000,000,000 years). Particle Physicists are trying to prove that this is indeed the case.

The decay of the proton is associated with a quark transformation in which an "up" quark is converted to a "down" quark by the weak interaction .

Decay of the Neutron

A free proton is virtually stable but a free neutron is comparitively very UNstable. It will decay with a half-life of about 10.3 minutes but it is considerably more stable if combined into a nucleus. It decays as beta decay with the emission of an electron and an electron antineutrino. The decay of the neutron involves the weak interaction as indicated in the Feynman diagrams on this page.

The decay of the neutron is associated with a quark transformation in which a "down" quark is converted to an "up" quark by the weak interaction .