MiniBooNE first results on a search for $$\nu_e$$ appearance at the $$\delta m^2\sim 1\ \hbox{ev}^2$$ scale
Solar and atmospheric neutrino oscillations, recently confirmed by reactor and accelerator-based experiments, are now well established. On the other hand, the interpretation of the LSND {bar {nu}}{sub e} excess [1] as {bar {nu}}{sub {mu}} {yields} {bar {nu}}{sub e} oscillations at the {Delta}m{sup 2} {approx} 1 eV{sup 2} scale lacked for many years experimental confirmation or refutation. The primary goal of the MiniBooNE experiment [2] is to address this anomaly in an unambiguous and independent way. The MiniBooNE flux is obtained via a high-intensity, conventional neutrino beam. Secondary hadrons, mostly pions and kaons, are produced via the interactions of 8 GeV protons from the Fermilab Booster accelerator with a thick beryllium target, and are focused by a horn. The switchable horn polarity allows for both neutrino and antineutrino running modes. The neutrino beam is produced via the decay of secondary mesons and muons in a 50 m long decay region. Overall, about 9.5 x 10{sup 20} protons on target have been accumulated over the five years of beamline operation, 5.6 x 10{sup 20} of which are used in this oscillation analysis, based on the neutrino running mode sample only. The MiniBooNE detector is located 540 m away from the beryllium target. The detector is a 12 m in diameter sphere filled with 800 t of undoped mineral oil, whose inner region is instrumented with 1280 photomultiplier tubes (PMTs). Neutrino interactions produce prompt, ring-distributed Cherenkov light, and delayed, isotropic scintillation light. Light transmission is affected by fluorescence, scattering, absorption and reflections. The outer detector region is used to reject cosmic ray activity or uncontained neutrino interactions. About 7.7 x 10{sup 5} neutrino interactions have been collected at MiniBooNE. The goal of the first MiniBooNE electron appearance analysis is two-fold: perform a model-independent search for a {nu}{sub e} excess (or deficit), and interpret the data within a two neutrino, appearance-only {nu}{sub {mu}} {yields} {nu}{sub e} oscillation context, to test this interpretation of the LSND anomaly [2]. This was a blind analysis.
- Research Organization:
- Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC02-07CH11359
- OSTI ID:
- 920424
- Report Number(s):
- FERMILAB-CONF-07-562-E; TRN: US0805573
- Resource Relation:
- Conference: Presented at 19th Conference on High Energy Physics (IFAE 2007), Naples, Italy, 11-13 Apr 2007
- Country of Publication:
- United States
- Language:
- English
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