MATTER INSTABILITY IN THE SU(5) UNIFIED MODEL OF STRONG, WEAK AND ELECTROMAGNETIC-INTERACTIONS

Previous estimates for the stability of matter through baryon-number violating nucleon decays are refined by taking into account all possible diagrams that contribute to the process. As a result, we obtain τ(p) ∼ τ(n) ∼ 1033y, not quite one order of magnitude smaller than previous estimates. Most of the decays will produce mesons, but no direct muon. Muon-producing decays are only ∼ 10% of all decays. Although the theoretical errors are large (about one order of magnitude) we conclude that, if the effect is there, and experiments sensitive to detection of mesons (and not only muons) are devised, an increase of two to three orders of magnitude in the present experimental accuracy may reveal it. © 1979.