Search for Proton Decay via p -> e+ pi0 in a Large Water Cherenkov Detector

TL;DR

This study searches for proton decay via p -> e+ pi0 in a large water Cherenkov detector, finding no candidates and setting a new lower limit on proton lifetime, contributing to understanding proton stability.

Contribution

It provides the most stringent lower limit on proton decay via p -> e+ pi0 using extensive water Cherenkov detector data.

Findings

No candidate events observed.

Background expected is 0.1 events.

Lower limit on proton lifetime is 1.6 x 10^33 years.

Abstract

We have searched for proton decay via p -> e+ pi0 using data from a 25.5 kton-year exposure of the Super-Kamiokande detector. We find no candidate events with an expected background induced by atmospheric neutrinos of 0.1 events. From these data, we set a lower limit on the partial lifetime of the proton to be 1.6E33 years at a 90% confidence level.