Proton decay
Proton decay is a theory that a proton could decay into two small particles, a pion and a positron. This would be a new type of radioactive decay. So far, proton decay has not been observed, but some physicists believe it. Most current theories say that protons do not decay.
Proton Decay Media
The pattern of weak isospins, weak hypercharges, and color charges for particles in the Georgi–Glashow model. Here, a proton, consisting of two up quarks and a down, decays into a pion, consisting of an up and anti-up, and a positron, via an X boson with electric charge −4/3.
R-parity violating rapid proton decay in MSSM
