Neutrino interactions with e/sup +/. mu. /sup -/ and multiple K/sup 0/'s. [Branching ratio]
A scan for directly produced positrons in 5,000 neutrino interactions in the neon (21 percent) hydrogen filled bubble chamber at Fermilab has yielded 15 events, 9 of which have ..mu../sup -/'s identified in the external muon identifier. On correcting for detection efficiency one obtains sigma(e/sup +/..mu../sup -/)/sigma(..mu../sup -/) approximately 1 x 10/sup -2/ for E/sub e/sup +// > .8 GeV and E/sub ..nu../ > 5 GeV. The kaon multiplicity is unexpectedly high. Eleven of the events have one or more Vees and three have two or more. Among the 11 events are two clear ..lambda..'s and two ambiguous K/sup 0//..lambda... There are four events with identifiable charged kaons. A 16th e/sup +/ event (9) is a definite ..nu../sub e/. From this information one concludes that the kaon multiplicity is 2 +- .6 K/sup 0/'s and 2 +- 1 K/sup + -/'s per interaction. From the observation / = 6.6, one concludes that the e/sup +/'s are probably not uniquely from heavy lepton decay. From a variety of analyses involving the e/sup +/ and/or K/sup 0/'s one learns that the mass of the hadron (C) that produces the e/sup +/'s is greater than 1.6 GeV. By determining the fraction of normal charged current (CC) events that have K/sup 0//sub s/ ..-->.. ..pi../sup +/..pi../sup -/ one is able to compare this fraction with the fraction of CC events that have e/sup +/..mu../sup -/ (K/sup 0//sub s/ ..-->.. ..pi../sup +/..pi../sup -/) to establish a conservative lower limit to the semileptonic branching ratio, C ..-->.. (e/sup +/ and ..mu../sup +/) ..nu../C ..-->.. all > 0.33 (1 +- .42), provided that the same number of K/sup 0//sub s/ exists in thenonleptonic decays as in the semileptonic ones, and that the phase space for ..mu../sup +/ and e/sup +/ are nearly equal. There is no compelling evidence for an energy threshold and there is a hint of some neutral current events among the e/sup +/ events.
- Research Organization:
- California Univ., Berkeley (USA). Lawrence Berkeley Lab.
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 7344517
- Report Number(s):
- LBL-5319; CONF-760719-17; TRN: 77-001659
- Resource Relation:
- Conference: 18. international conference on high energy physics, Tbilisi, USSR, 15 Jul 1976
- Country of Publication:
- United States
- Language:
- English
Similar Records
Phi meson and accompanying strange particle production in 16 GeV/c. pi. /sup +/p interactions. Final report
First measurement of the ratio of branching fractions B({lambda}{sub b}{sup 0}{yields}{lambda}{sub c}{sup +}{mu}{sup -}{nu}{sub {mu}})/B({lambda}{sub b}{sup 0}{yields}{lambda}{sub c}{sup +}{pi}{sup -})
Related Subjects
HADRONS
LEPTONIC DECAY
KAONS
MULTIPLE PRODUCTION
NEUTRINO-NUCLEON INTERACTIONS
NEUTRAL CURRENTS
ANTINEUTRINOS
BUBBLE CHAMBERS
ELECTRON NEUTRINOS
HYDROGEN
KAONS MINUS
KAONS NEUTRAL
KAONS PLUS
LAMBDA PARTICLES
MASS
MULTIPLICITY
MUONS MINUS
NEON
PARTICLE PRODUCTION
PHASE SPACE
POSITRONS
THRESHOLD ENERGY
ALGEBRAIC CURRENTS
ANTILEPTONS
ANTIMATTER
ANTIPARTICLES
BARYONS
BASIC INTERACTIONS
BOSONS
CRYOGENIC FLUIDS
CURRENTS
DECAY
ELEMENTARY PARTICLES
ELEMENTS
ENERGY
FERMIONS
FLUIDS
GAS TRACK DETECTORS
HYPERONS
INTERACTIONS
LEPTON-BARYON INTERACTIONS
LEPTON-HADRON INTERACTIONS
LEPTON-NUCLEON INTERACTIONS
LEPTONS
MASSLESS PARTICLES
MATHEMATICAL SPACE
MEASURING INSTRUMENTS
MESONS
MUONS
NEUTRINOS
NONMETALS
PARTICLE DECAY
PARTICLE INTERACTIONS
PSEUDOSCALAR MESONS
RADIATION DETECTORS
RARE GASES
SPACE
STRANGE PARTICLES
WEAK INTERACTIONS
WEAK PARTICLE DECAY
645104* - High Energy Physics- Particle Interactions & Properties-Experimental- Strong Meson-Induced Interactions- (-1987)
645101 - High Energy Physics- Particle Interactions & Properties-Experimental- Electromagnetic Interactions & Properties