Search for nucleon decay via modes favored by supersymmetric grand unification models in Super-Kamiokande-I

Abstract

We report the results for nucleon decay searches via modes favored by supersymmetric grand unified models in Super-Kamiokande. Using 1489 days of full Super-Kamiokande-I data, we searched for $p\ensuremath{\rightarrow}\overline{\ensuremath{\nu}}{K}^{+}$, $n\ensuremath{\rightarrow}\overline{\ensuremath{\nu}}{K}^{0}$, $p\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{K}^{0}$, and $p\ensuremath{\rightarrow}{e}^{+}{K}^{0}$ modes. We found no evidence for nucleon decay in any of these modes. We set lower limits of partial nucleon lifetime $2.3\ifmmode\times\else\texttimes\fi{}{10}^{33}$, $1.3\ifmmode\times\else\texttimes\fi{}{10}^{32}$, $1.3\ifmmode\times\else\texttimes\fi{}{10}^{33}$, and $1.0\ifmmode\times\else\texttimes\fi{}{10}^{33}\text{ }\text{ }\mathrm{years}$ at 90% confidence level for $p\ensuremath{\rightarrow}\overline{\ensuremath{\nu}}{K}^{+}$, $n\ensuremath{\rightarrow}\overline{\ensuremath{\nu}}{K}^{0}$, $p\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{K}^{0}$, and $p\ensuremath{\rightarrow}{e}^{+}{K}^{0}$ modes, respectively. These results give a strong constraint on supersymmetric grand unification models.