First nucleon decay results from the Soudan 2 detector

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1992

OSTI ID:7233324

Schmid, D J

The Soudan 2 detector is a large tracking calorimeter designed to search for nucleon decay and other rare phenomenon. The detector is located 2340 feet underground in a northern Minnesota iron mine. Although the detector is still under construction (completion is scheduled for late 1992), a data sample representing 0.50 fiducial kTon [center dot] yrs of exposure has been collected and analyzed. The Soudan 2 detector provides a great deal of information about each event, which allowed several different pattern recognition techniques to be applied to the problem of distinguishing nucleon decays from neutrino background events. A 90% confidence level limit of [tau]/B > 4.5 [center dot] 10[sup 30] years was set on the proton decay mode p [yields] vK[sup +] with an expected background from atmospheric neutrino interactions of less than 0.10 event. Also, limits on the modes n [yields] e[sup [minus]]K[sup +] ([tau]/B > 7.5 [center dot] 10[sup 30] years) and n [yields] [mu][sup [minus]]K[sup +] ([tau]/B > 6.5 [center dot] 10[sup 30] years) were obtained, with expected neutrino backgrounds of less than 0.04 event.

• Research Organization: Minnesota Univ., Minneapolis, MN (United States)
• OSTI ID: 7233324
• Country of Publication: United States
• Language: English

Related Subjects

440104 -- Radiation Instrumentation-- High Energy Physics Instrumentation
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
662360* -- Decays of Baryons-- (1992-)
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BARYONS
DECAY
ELEMENTARY PARTICLES
FERMIONS
HADRONS
LEPTONS
MASSLESS PARTICLES
MEASURING INSTRUMENTS
NEUTRINOS
NUCLEONS
PARTICLE DECAY
PATTERN RECOGNITION
RADIATION DETECTORS
SHOWER COUNTERS