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Title: Resolving {theta}{sub 23} degeneracy by accelerator and reactor neutrino oscillation experiments

Abstract

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.

Authors:
;  [1];  [2];  [3];  [4]; ;  [5]
  1. Department of Physics, Kyoto University, 606-8502, Kyoto (Japan)
  2. Department of Physics, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397 (Japan)
  3. Departamento de Fisica, Pontificia Universidade Catolica do Rio de Janeiro, C. P. 38071, 22452-970, Rio de Janeiro (Brazil)
  4. Theory Group, KEK, Tsukuba, Ibaraki 305-0801 (Japan)
  5. Instituto de Fisica, Universidade de Sao Paulo, C. P. 66.318, 05315-970 Sao Paulo (Brazil)
Publication Date:
OSTI Identifier:
20782974
Resource Type:
Journal Article
Journal Name:
Physical Review. D, Particles Fields
Additional Journal Information:
Journal Volume: 73; Journal Issue: 9; Other Information: DOI: 10.1103/PhysRevD.73.093008; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0556-2821
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ELECTRON NEUTRINOS; ERRORS; MATHEMATICAL SOLUTIONS; MUON NEUTRINOS; NEUTRINO OSCILLATION; STANDARD MODEL; WEINBERG ANGLE

Citation Formats

Hiraide, K, Nakaya, T, Minakata, H, Nunokawa, H, Sugiyama, H, Teves, W J.C., and Funchal, R Zukanovich. Resolving {theta}{sub 23} degeneracy by accelerator and reactor neutrino oscillation experiments. United States: N. p., 2006. Web. doi:10.1103/PHYSREVD.73.093008.
Hiraide, K, Nakaya, T, Minakata, H, Nunokawa, H, Sugiyama, H, Teves, W J.C., & Funchal, R Zukanovich. Resolving {theta}{sub 23} degeneracy by accelerator and reactor neutrino oscillation experiments. United States. https://doi.org/10.1103/PHYSREVD.73.093008
Hiraide, K, Nakaya, T, Minakata, H, Nunokawa, H, Sugiyama, H, Teves, W J.C., and Funchal, R Zukanovich. Mon . "Resolving {theta}{sub 23} degeneracy by accelerator and reactor neutrino oscillation experiments". United States. https://doi.org/10.1103/PHYSREVD.73.093008.
@article{osti_20782974,
title = {Resolving {theta}{sub 23} degeneracy by accelerator and reactor neutrino oscillation experiments},
author = {Hiraide, K and Nakaya, T and Minakata, H and Nunokawa, H and Sugiyama, H and Teves, W J.C. and Funchal, R Zukanovich},
abstractNote = {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.},
doi = {10.1103/PHYSREVD.73.093008},
url = {https://www.osti.gov/biblio/20782974}, journal = {Physical Review. D, Particles Fields},
issn = {0556-2821},
number = 9,
volume = 73,
place = {United States},
year = {2006},
month = {5}
}