title: Is the proton stable.
abstract: For nearly 50 years there has been a strong belief that the proton is absolutely stable. The current experimental upper bound on its decay rate is less than one proton decay per 3 tons of matter per year, which corresponds to a mean lifetime of more than 10(30) years. Even more sensitive searches for proton decay are now in progress. These are partially motivated by the development of a class of models that combine the presently accepted theories of electromagnetic, weak, and strong inter-actions into an elegant unified form. Some of these theories predict a proton lifetime short enough for the decays to be detectable by the proposed experiments. If the proton is unstable, a plausible explanation can be given for the apparent excess of matter over antimatter in the universe.
authors.forename: M
authors.initials: M
authors.lastname: Goldhaber
authors.forename: P
authors.initials: P
authors.lastname: Langacker
authors.forename: R
authors.initials: R
authors.lastname: Slansky