Long-baseline neutrino oscillation experiment at the San Onofre reactor
- California Institute of Technology, Pasadena, CA (United States)
Study of neutrino oscillations remain a powerful probe for electroweak physics. The early experiments, using neutrinos from nuclear reactors at the ILL Grenoble and at Goesgen, have shown that neutrino mixing and neutrino masses, as proposed in some theoretical models, must be very small. Specifically, limits were set for the mass parameter, {Delta}m{sup 2}, of 2 x 10{sup {minus}2} eV{sup 2}, with limits for the mixing amplitude of about 0.1, putting to rest earlier claims for neutrino oscillations. Much of the parameter space suggested by the atmospheric results, {Delta}m{sup 2} between 10{sup {minus}2} and 10{sup {minus}3} eV{sup 2} and large mixing angles, remains unexplored as it is outside the range of previous reactor or accelerator experiments. Thus, measurements with more sensitive detectors are needed to shed light on both, {bar {nu}}{sub e} and {bar {nu}}{sub {mu}} disappearance. With this goal in mind, the authors group is now building a fine-grain 12-ton 0.1% Gd-loaded scintillation detector, to be installed underground (25 mwe) at a distance of 0.7 km from the San Onofre reactor station in Southern California. In this segmented low energy detector, a positron created by the reactor {bar {nu}}{sub e} in the reaction {bar {nu}}{sub e} + p {yields} e{sup +} + n, is identified by a triple coincidence between positron and two annihilation gammas in adjacent detector elements, a scheme permitting significant reduction of backgrounds, such as those associated with neutrons from cosmic-ray muon interactions. In addition, the neutron accompanying the positron is registered by the 8 MeV gamma cascade following capture in Gd in the scintillator, thus allowing a threshold setting well above the radioactive backgrounds. The experiment will provide a definitive answer as to whether the atmospheric results signal {bar {nu}}{sub {mu}} {leftrightarrow} {bar {nu}}{sub e} oscillations.
- OSTI ID:
- 374985
- Report Number(s):
- CONF-9304297-; ISSN 0003-0503; TRN: 96:004080-0377
- Journal Information:
- Bulletin of the American Physical Society, Vol. 40, Issue 2; Conference: 1993 joint meeting of the American Physical Society and the American Association of Physics Teachers, Washington, DC (United States), 12-15 Apr 1993; Other Information: PBD: Apr 1995
- Country of Publication:
- United States
- Language:
- English
Similar Records
A proposal to search for neutrino oscillations with high sensitivity in the appearance channels. nu. sub. mu. yields. nu. sub e and. nu. sub. mu. yields. nu. sub e
Search for neutrino oscillations at a fission reactor