Search for proton decay into muon and neutral Kaon in Super-Kamiokande

Verification of the Grand Unified Theory is one of the most important subjects in particle physics. In this poster, we will present new result of the search for p→μ+K0 decay mode in Super-Kamiokande. This decay mode is motivated by some Supersymmetric (SUSY) GUT models in which the dominant mode has a different generation of quarks in the final state due to the contribution of the color triplet Higgs boson. The signal is distinguished from the atmospheric neutrino background. The analysis method was updated using an improved event reconstruction algorithm and the selection criteria were optimized separately for K0S and K0L decay accounting for the different lifetimes. As a result of the search, no candidates were remained in the additional 0.2 Mton * year data. We set lower a limit on the partial proton lifetime as 3.6×1033 years at a 90% confidence level from 0.37 Mton * year data analyzed so far. Our new lifetime lower limit is the most stringent in the world and better than the previous published SK I-III result more than factor 2.