Search for proton decay into positron plus neutral pion and positive muon plus neutral pion

Thesis/Dissertation · Sat Jan 01 04:00:00 EST 1983

OSTI ID:6466733

Wuest, C R

132 days of data corresponding to 4 x 10/sup 32/ proton years of exposure has been analyzed in the Irvine-Michigan-Brookhaven water Cerenkov nucleon decay detector. The analysis has concentrated on multi-track contained events in which the tracks are thought to be the likely products of proton decay with lifetimes of 10/sup 30/ to 10/sup 32/ years as predicted in the recent grand unification theories. 18.5 million event triggers were scanned for the decay modes: p ..-->.. e/sup +/..pi../sup 0/, and ..mu../sup +/..pi../sup 0/. No events are observed for the e/sup +/..pi../sup 0/ mode from either free or bound protons. Based on this, a new lower limit on the lifetime of the proton for this postulated mode divided by the branching ratio at the 90% confidence level is: tau/B (all p ..-->.. e/sup +/..pi../sup 0/) greater than or equal to 8.1 x 10/sup 31/ years. In addition a lifetime independent of nuclear effects for the e/sup +/..pi../sup 0/ mode can be obtained and is: tau/B (free p ..-->.. e/sup +/..pi../sup 0/) greater than or equal to 2.4 x 10/sup 31/ years. Two candidates consistent with the expected neutrino background are observed as potential ..mu../sup +/..pi../sup 0/ bound proton decay and no candidates are seen satisfying the requirements for decay from free protons. The calculated lifetimes are: tau/B (all p ..-->.. ..mu../sup +/..pi../sup 0/) greater than or equal to 3.4 x 10/sup 31/ years and tau/B (free p ..-->.. ..mu../sup +/..pi../sup 0/) greater than or equal to 2.3 x 10/sup 31/ years.

• Research Organization: California Univ., Irvine (USA)
• OSTI ID: 6466733
• Country of Publication: United States
• Language: English

Related Subjects

645102* -- High Energy Physics-- Particle Interactions & Properties-Experimental-- Weak Interactions & Properties
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANTILEPTONS
ANTIMATTER
ANTIPARTICLES
BARYONS
BOSONS
BRANCHING RATIO
DATA
DECAY
ELEMENTARY PARTICLES
EXPERIMENTAL DATA
FERMIONS
HADRONS
INFORMATION
LEPTONS
LIFETIME
LIMITING VALUES
MESONS
MUONS
MUONS PLUS
NUCLEONS
NUMERICAL DATA
PARTICLE DECAY
PIONS
PIONS NEUTRAL
POSITRONS
PROTONS
PSEUDOSCALAR MESONS
SEMILEPTONIC DECAY
WEAK PARTICLE DECAY