A search for. nu. sub e appearance from stopped. pi. sup + and. mu. sup + decay at LAMPF (Los Alamos Meson Physics Facility)

Technical Report · Mon Jan 01 04:00:00 EST 1990

DOI:https://doi.org/10.2172/5093548· OSTI ID:5093548

Fujikawa, B K ^[1]

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1. California Inst. of Tech., Pasadena, CA (USA). Dept. of Physics

We report on a recent search for {bar {nu}}{sub e} appearance from stopped {pi}{sup +} {yields} {mu}{sup +}{nu}{sub {mu}} and {mu}{sup +} {yields} e{sup +}{nu}{sub e}{bar {nu}}{sub {mu}} decay made by the LAMPF experiment E645. The appearance of {bar {nu}}{sub e} may occur from {bar {nu}}{sub {mu}} {yields} {bar {nu}}{sub e}, {nu}{sub e} {yields} {bar {nu}}{sub eL}, or {nu}{sub {mu}} {yields} {bar {nu}}{sub eL} oscillations. Appearance may also occur from rare {mu}{sup +} {yields} e{sup +}{bar {nu}}{sub e}{nu}{sub {mu}} decay, which is allowed by a multiplicative lepton charge conservation law. The neutrino energies range from E{sub {nu}} = 0 to 52.8MeV. The neutrino detector, which is located 26.1 meters from the neutrino source, consists of a segmented liquid scintillator and proportional drift tube central detector surrounded by both active and passive shielding. The central detector detects {bar {nu}}{sub e} through the {bar {nu}}{sub e}p {yields} ne{sup +} Charge Current (CC) reaction, which is signaled by the direct detection of the final state positron and neutron. The hydrogen-rich liquid scintillators act as free proton targets for the {bar {nu}}{sub e}p CC reaction. The neutrons are detected through radiative neutron capture on gadolinium. We find no evidence for {bar {nu}}{sub e} appearance in the first year of running. New limits on the {bar {nu}}{sub {mu}},{nu}{sub e},{nu}{sub {mu}} {yields} {bar {nu}}{sub e} oscillation parameters and the rare {mu}{sup +} {yields} e{sup +}{bar {nu}}{sub e}{nu}{sub {mu}} decay branching ratio are presented. 87 refs., 45 figs., 17 tabs.

• Research Organization: Los Alamos National Lab., NM (USA)
• Sponsoring Organization: DOE/ER
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 5093548
• Report Number(s): LA-11721-T; ON: DE90005833
• 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
ANTINEUTRINOS
ANTIPARTICLES
BARYON REACTIONS
BOSONS
BRANCHING RATIO
CAPTURE
CONSERVATION LAWS
DATA
DECAY
DETECTION
ELECTRON ANTINEUTRINOS
ELECTRON NEUTRINOS
ELEMENTARY PARTICLES
ELEMENTS
ENERGY RANGE
EXPERIMENTAL DATA
FERMIONS
GADOLINIUM
HADRON REACTIONS
HADRONS
INFORMATION
LEPTON NUMBER
LEPTONS
LIQUID SCINTILLATORS
MASSLESS PARTICLES
MEASURING INSTRUMENTS
MESONS
METALS
MEV RANGE
MEV RANGE 10-100
MUONS
MUONS PLUS
NEUTRINO DETECTION
NEUTRINOS
NEUTRON REACTIONS
NUCLEAR REACTIONS
NUCLEON REACTIONS
NUMERICAL DATA
PARTICLE DECAY
PHOSPHORS
PIONS
PIONS PLUS
PROPORTIONAL COUNTERS
PSEUDOSCALAR MESONS
RADIATION DETECTION
RADIATION DETECTORS
RARE EARTHS