A Search for Nucleon Decay via $n \rightarrow \bar{\nu} \pi^{0}$ and $p \rightarrow \bar{\nu} \pi^{+}$ in Super-Kamiokande

TL;DR

This study searches for specific nucleon decay modes in Super-Kamiokande data, setting new lower limits on their partial lifetimes, which constrains theories predicting such decay processes.

Contribution

First comprehensive search for nucleon decay via these modes using extensive Super-Kamiokande data, establishing new lifetime limits.

Findings

Partial lifetime for antineutrino pizero >1.1x10^{33} years

Partial lifetime for antineutrino piplus >3.9x10^{32} years

No evidence of nucleon decay observed

Abstract

We present the results of searches for nucleon decay via bound neutron to antineutrino plus pizero and proton to antineutrino plus piplus using data from a combined 172.8 kiloton-years exposure of Super-Kamiokande-I, -II, and -III. We set lower limits on the partial lifetime for each of these modes. For antineutrino pizero, the partial lifetime is >1.1x10^{33} years; for antineutrino piplus, the partial lifetime is >3.9x10^{32} years at 90% confidence level.