Stability of the proton AS Level Notes

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 .

Proton Decay 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.

Neutron Decay The decay of the neutron involves the weak interaction as indicated in the Feynman diagrams you know.

Neutron Decay 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.