Search for the Proton Decay Mode proton to neutrino K+ in Soudan 2

We have searched for the proton decay mode proton to neutrino K+ using the one-kiloton Soudan 2 high resolution calorimeter. Contained events obtained from a 3.56 kiloton-year fiducial exposure through June 1997 are examined for occurrence of a visible K+ track which decays at rest into mu+ nu or pi+ pi0. We found one candidate event consistent with background, yielding a limit, tau/B > 4.3 10^{31} years at 90% CL with no background subtraction.Comment: 13 pages, Latex, 3 tables and 3 figures, Accepted by Physics Letters

Search for the proton decay mode p ->nu K+ in Soudan 2

We have searched for the proton decay mode p → ν K+ using the one-kiloton Soudan 2 high resolution calorimeter. Contained events obtained from a 3.56 kiloton-year fiducial exposure through June 1997 are examined for occurrence of a visible K+ track which decays at rest into μ+ ν or π+ π0. We found one candidate event consistent with background, yielding a limit, τ/B(p → ν K+) > 4.3 × 1031 years at 90% CL with no background subtraction. © 1998 Published by Elsevier Science B.V. All rights reserved