Baryon-Conservation Limit

An improved lower limit of g2 \ifmmode\times\else\texttimes\fi{} ${10}^{30}$ yr against baryon-conservation-violating nucleon decay has been obtained for modes which produce $\ensuremath{\mu}\ensuremath{\rightarrow}e$ decays. The detector, employing a 20-ton large-area (180 ${\mathrm{m}}^{2}$) liquid scintillator, was operated deep underground (3.2 km) to eliminate stopping muons from cosmic rays, leaving only the background from muons produced by atmospheric neutrinos. A run length of 2.7 yr was required to achieve the sensitivity quoted.