The ν̄e flux and spectrum have been measured at a distance of about 800 m from the reactors of the Palo Verde Nuclear Generating Station using a segmented Gd-loaded liquid scintillator detector. Correlated positron-neutron events from the reaction ν̄ep-→e+n were recorded for a period of 200 d including 55 d with one of the three reactors off for refueling. Backgrounds were accounted for by making use of the reactor-on and reactor-off cycles, and also with a novel technique based on the difference between signal and background under reversal of the e+ and n portions of the events. A detailed description of the detector calibration, background subtraction, and data analysis is presented here. Results from the experiment show no evidence for neutrino oscillations. ν̄e→ν̄x oscillations were excluded at 90% C.L. for Δm2>1.12×10-3 eV2 for full mixing and sin22θ>0.21 for large Δm2. These results support the conclusion that the observed atmospheric neutrino oscillations do not involve νe.
|Original language||English (US)|
|Number of pages||18|
|Journal||Physical Review D - Particles, Fields, Gravitation and Cosmology|
|State||Published - Oct 1 2000|
ASJC Scopus subject areas
- Nuclear and High Energy Physics
- Physics and Astronomy (miscellaneous)