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Title: Resolving parameter degeneracies in long-baseline experiments by atmospheric neutrino data

Abstract

In this work we show that the physics reach of a long-baseline (LBL) neutrino oscillation experiment based on a superbeam and a megaton water Cherenkov detector can be significantly increased if the LBL data are combined with data from atmospheric neutrinos (ATM) provided by the same detector. ATM data are sensitive to the octant of {theta}{sub 23} and to the type of the neutrino mass hierarchy, mainly through three-flavor effects in e-like events. This allows to resolve the so-called {theta}{sub 23}- and sign({delta}m{sub 31}{sup 2})-parameter degeneracies in LBL data. As a consequence it becomes possible to distinguish the normal from the inverted neutrino mass ordering at 2{sigma} C.L. from a combined LBL+ATM analysis if sin{sup 2}2{theta}{sub 13} > or approx. 0.02. The potential to identify the true values of sin{sup 2}2{theta}{sub 13} and the CP-phase {delta}{sub CP} is significantly increased through the lifting of the degeneracies. These claims are supported by a detailed simulation of the T2K (phase II) LBL experiment combined with a full three-flavor analysis of ATM data in the HyperKamiokande detector.

Authors:
 [1];  [2];  [3]
  1. Department of Physics, University of Wisconsin, 1150 University Avenue, Madison, Wisconsin 53706 (United States)
  2. C.N. Yang Institute for Theoretical Physics, SUNY at Stony Brook, Stony Brook, New York 11794-3840 (United States)
  3. Scuola Internazionale Superiore di Studi Avanzati, Via Beirut 2-4, I-34014 Trieste (Italy)
Publication Date:
OSTI Identifier:
20706090
Resource Type:
Journal Article
Journal Name:
Physical Review. D, Particles Fields
Additional Journal Information:
Journal Volume: 71; Journal Issue: 5; Other Information: DOI: 10.1103/PhysRevD.71.053006; (c) 2005 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; CHERENKOV COUNTERS; COMPUTERIZED SIMULATION; CP INVARIANCE; FLAVOR MODEL; NEUTRINO OSCILLATION; NEUTRINOS; REST MASS

Citation Formats

Huber, Patrick, Maltoni, Michele, and Schwetz, Thomas. Resolving parameter degeneracies in long-baseline experiments by atmospheric neutrino data. United States: N. p., 2005. Web. doi:10.1103/PhysRevD.71.053006.
Huber, Patrick, Maltoni, Michele, & Schwetz, Thomas. Resolving parameter degeneracies in long-baseline experiments by atmospheric neutrino data. United States. https://doi.org/10.1103/PhysRevD.71.053006
Huber, Patrick, Maltoni, Michele, and Schwetz, Thomas. Tue . "Resolving parameter degeneracies in long-baseline experiments by atmospheric neutrino data". United States. https://doi.org/10.1103/PhysRevD.71.053006.
@article{osti_20706090,
title = {Resolving parameter degeneracies in long-baseline experiments by atmospheric neutrino data},
author = {Huber, Patrick and Maltoni, Michele and Schwetz, Thomas},
abstractNote = {In this work we show that the physics reach of a long-baseline (LBL) neutrino oscillation experiment based on a superbeam and a megaton water Cherenkov detector can be significantly increased if the LBL data are combined with data from atmospheric neutrinos (ATM) provided by the same detector. ATM data are sensitive to the octant of {theta}{sub 23} and to the type of the neutrino mass hierarchy, mainly through three-flavor effects in e-like events. This allows to resolve the so-called {theta}{sub 23}- and sign({delta}m{sub 31}{sup 2})-parameter degeneracies in LBL data. As a consequence it becomes possible to distinguish the normal from the inverted neutrino mass ordering at 2{sigma} C.L. from a combined LBL+ATM analysis if sin{sup 2}2{theta}{sub 13} > or approx. 0.02. The potential to identify the true values of sin{sup 2}2{theta}{sub 13} and the CP-phase {delta}{sub CP} is significantly increased through the lifting of the degeneracies. These claims are supported by a detailed simulation of the T2K (phase II) LBL experiment combined with a full three-flavor analysis of ATM data in the HyperKamiokande detector.},
doi = {10.1103/PhysRevD.71.053006},
url = {https://www.osti.gov/biblio/20706090}, journal = {Physical Review. D, Particles Fields},
issn = {0556-2821},
number = 5,
volume = 71,
place = {United States},
year = {2005},
month = {3}
}