Is the Proton Stable
M. Goldhaber 1,
P. Langacker 2, and
R. Slansky 3
1 AUI Distinguished Scientist at Brookhaven National Laboratory, Associated Universities, Incorporated, Upton, New York 11973
2 Assistant professor in the Department of Physics, University of Pennsylvania, Philadelphia 19104
3 Member of the staff in the Theoretical Division, Los Alamos Scientific Laboratory, University of California, Los Alamos, New Mexico 87545
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 1030 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.
