Resolving {theta}{sub 23} degeneracy by accelerator and reactor neutrino oscillation experiments
- Department of Physics, Kyoto University, 606-8502, Kyoto (Japan)
- Department of Physics, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397 (Japan)
- Departamento de Fisica, Pontificia Universidade Catolica do Rio de Janeiro, C. P. 38071, 22452-970, Rio de Janeiro (Brazil)
- Theory Group, KEK, Tsukuba, Ibaraki 305-0801 (Japan)
- Instituto de Fisica, Universidade de Sao Paulo, C. P. 66.318, 05315-970 Sao Paulo (Brazil)
If the lepton mixing angle {theta}{sub 23} is not maximal, there arises a problem of ambiguity in determining {theta}{sub 23} due to the existence of two degenerate solutions, one in the first and the other in the second octant. We discuss an experimental strategy for resolving the {theta}{sub 23} octant degeneracy by combining reactor measurement of {theta}{sub 13} with accelerator {nu}{sub {mu}} disappearance and {nu}{sub e} appearance experiments. The robustness of the {theta}{sub 23} degeneracy and the difficulty in lifting it only by accelerator experiments with conventional {nu}{sub {mu}} (and {nu}{sub {mu}}) beams are demonstrated by analytical and numerical treatments. Our method offers a way to overcome the difficulty and can resolve the degeneracy between solutions sin{sup 2}{theta}{sub 23}=0.4 and sin{sup 2}{theta}{sub 23}=0.6 if sin{sup 2}2{theta}{sub 13} > or approx. 0.05 at 95% CL by assuming the T2K phase II experiment and a reactor measurement with an exposure of 10 GW{center_dot}kt{center_dot}yr. The dependence of the resolving power of the octant degeneracy on the systematic errors of reactor experiments is also examined.
- OSTI ID:
- 20782974
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 73, Issue 9; Other Information: DOI: 10.1103/PhysRevD.73.093008; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
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