Studies in the BNL 21-GeV/c negative-hyperon beam. II. Leptonic decays of. xi. and. sigma

Journal Article · Tue Jan 01 04:00:00 EST 1980 · Phys. Rev., D; (United States)

DOI:https://doi.org/10.1103/PhysRevD.21.25· OSTI ID:5729280

Thompson, J A; Cleland, W E; Cooper, W E; Dris, M; Engles, E Jr; Herbert, M L; Kraus, D E; Lowenstein, D

The decays ..sigma../sup -/ ..-->.. ..lambda..e/sup -/..nu.. and ..xi../sup -/ ..-->.. ..lambda..e/sup -/..nu.. are studied in a counter--spark-chamber experiment using unpolarized hyperons from the BNL hyperon beam. A threshold Cerenkov counter identifies the electron. From a sample of 119 reconstructed ..sigma../sup -/ ..-->.. ..lambda..e/sup -/..nu.. events (including approx. 5 background events), we find (..sigma../sup -/ ..-->.. ..lambda..e/sup -/..nu..)/(..sigma../sup -/ ..-->.. n..pi..) = (0.63 +- 0.10) x 10/sup -4/ and g/sub V//g/sub A/=-0.32 +- 0.30, g/sub W/M=-0.6 +- 3.6 (with sign convention of the Particle Data Group tables). We find Im(g/sub V//g/sub A/) =0.2 +- 0.7, consistent with time-reversal invariance. From a sample of 14 ..xi../sup -/ ..-->.. ..lambda..e/sup -/..nu.. events (including approx. = 3.4 background events) we find (..xi../sup -/ ..-->.. ..lambda..e/sup -/..nu..)/(..xi../sup -/ ..-->.. ..lambda pi..= (0.30 +- 0.14) x 10/sup -3/. We also searched for ..xi../sup -/ ..-->.. ..lambda mu nu.. and ..xi../sup -/ ..-->.. ..sigma../sup 0/e..nu.. and set upper limits on these decays from our data.

• Research Organization: University of Pittsburgh, Pittsburgh, Pennsylvania 15260
• OSTI ID: 5729280
• Journal Information: Phys. Rev., D; (United States), Journal Name: Phys. Rev., D; (United States) Vol. 21:1; ISSN PRVDA
• 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
BARYONS
BEAMS
BRANCHING RATIO
CABIBBO ANGLE
CHERENKOV COUNTERS
DALITZ PLOT
DECAY
DIAGRAMS
ELECTRON NEUTRINOS
ELECTRONS
ELEMENTARY PARTICLES
ENERGY RANGE
FERMIONS
GAS TRACK DETECTORS
GEV RANGE
GEV RANGE 10-100
HADRONS
HYPERON BEAMS
HYPERONS
INTERACTIONS
INVARIANCE PRINCIPLES
ISOSPIN
LAMBDA PARTICLES
LEPTONS
LIFETIME
MASSLESS PARTICLES
MATRIX ELEMENTS
MEASURING INSTRUMENTS
NEUTRINOS
PARTICLE BEAMS
PARTICLE DECAY
PARTICLE INTERACTIONS
PARTICLE PRODUCTION
PARTICLE PROPERTIES
RADIATION DETECTORS
SCATTERPLOTS
SEMILEPTONIC DECAY
SIGMA MINUS
SIGMA PARTICLES
SPARK CHAMBERS
STRANGE PARTICLES
T INVARIANCE
WEAK PARTICLE DECAY
XI MINUS
XI PARTICLES