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Electron neutrino and antineutrino appearance in the full MINOS data sample
P Adamson1, I Anghel, C Backhouse
1Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA.
Physical Review Letters
|May 18, 2013
Summary
The MINOS experiment observed electron neutrinos and antineutrinos appearing in muon neutrino and antineutrino beams. This study probes neutrino mixing parameters, including the mass hierarchy and CP violation phase (δ).
Area of Science:
- Particle Physics
- Neutrino Oscillations
- High-Energy Physics
Background:
- Neutrino oscillations are a key phenomenon in particle physics, demonstrating that neutrinos have mass.
- Understanding neutrino mixing parameters is crucial for completing the Standard Model and exploring new physics.
- The MINOS experiment utilizes long-baseline neutrino beams to study these oscillations.
Purpose of the Study:
- To report on the appearance of electron neutrinos (νe) and electron antineutrinos (νe) in muon neutrino (νμ) and muon antineutrino (νμ) beams.
- To probe the neutrino mass hierarchy, the θ23 octant degeneracy, and the CP-violating phase (δ) using a 735 km baseline.
- To perform the first accelerator long-baseline search for muon neutrino to electron neutrino (νμ → νe) appearance.
Main Methods:
- Utilized the full MINOS data sample for analyzing neutrino and antineutrino interactions.
- Compared observed νe and νe appearance data with θ13 measurements from reactor experiments.
- Employed a 735 km baseline to enhance sensitivity to oscillation parameters.
Main Results:
- The analysis disfavors 31% (5%) of the three-parameter space (δ, θ23 octant, mass hierarchy) at the 68% (90%) confidence level.
- Measured a value of 2sin²(2θ13)sin²(θ23) consistent with results from reactor experiments.
- Achieved the first accelerator long-baseline search for νμ → νe appearance.
Conclusions:
- The MINOS data provide significant constraints on neutrino oscillation parameters.
- The results contribute to resolving the θ23 octant degeneracy and determining the neutrino mass hierarchy.
- The consistency with reactor experiments validates the understanding of θ13.
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