skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: A Monochromatic Neutrino Beam to Obtain U(e3) and the CP Phase

Abstract

The goal for future neutrino facilities is the determination of the [Ue3] mixing and CP violation in neutrino oscillations. This will require precision experiments with a very intense neutrino source. The future experiments such as T2K, NOVA and Double CHOOZ will measure the [Ue3] mixing. In order to explore CP violation, we present a novel method to create a monochromatic neutrino beam based on the recent discovery of nuclei that decay fast through electron capture in a superallowed Gamow-Teller transition. The boost of such radioactive ions will generate an intense monochromatic directional neutrino beam when decaying at high energy in a storage ring with long straight sections. We show that the capacity of such a facility to discover new physics is impressive, so that the principle of energy dependence in the oscillation probability of the suppressed {nu}e {yields} {nu}{mu} channel is operational to separate out the two parameters of the mixing {theta}13 and the CP-violating phase {delta}.

Authors:
; ;  [1];  [2];  [3]
  1. Universitat de Valencia, E-46100 Burjassot, Valencia (Spain)
  2. (Spain)
  3. AB-division, CERN, Geneva (Switzerland)
Publication Date:
OSTI Identifier:
21054793
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 885; Journal Issue: 1; Conference: EAV06: Advanced summer school in physics 2006: Frontiers in contemporary physics, Mexico City (Mexico), 10-14 Jul 2006; Other Information: DOI: 10.1063/1.2563182; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; BETA DECAY; CP INVARIANCE; ELECTRON CAPTURE; ENERGY DEPENDENCE; GAMOW-TELLER RULES; MONOCHROMATIC RADIATION; NEUTRINO BEAMS; NEUTRINO OSCILLATION; NEUTRINOS; PROBABILITY; REST MASS; STORAGE RINGS

Citation Formats

Espinoza, C., Bernabeu, J., Burguet-Castell, J., IFIC, E-46100 Burjassot, Valencia, and Lindroos, M.. A Monochromatic Neutrino Beam to Obtain U(e3) and the CP Phase. United States: N. p., 2007. Web. doi:10.1063/1.2563182.
Espinoza, C., Bernabeu, J., Burguet-Castell, J., IFIC, E-46100 Burjassot, Valencia, & Lindroos, M.. A Monochromatic Neutrino Beam to Obtain U(e3) and the CP Phase. United States. doi:10.1063/1.2563182.
Espinoza, C., Bernabeu, J., Burguet-Castell, J., IFIC, E-46100 Burjassot, Valencia, and Lindroos, M.. Fri . "A Monochromatic Neutrino Beam to Obtain U(e3) and the CP Phase". United States. doi:10.1063/1.2563182.
@article{osti_21054793,
title = {A Monochromatic Neutrino Beam to Obtain U(e3) and the CP Phase},
author = {Espinoza, C. and Bernabeu, J. and Burguet-Castell, J. and IFIC, E-46100 Burjassot, Valencia and Lindroos, M.},
abstractNote = {The goal for future neutrino facilities is the determination of the [Ue3] mixing and CP violation in neutrino oscillations. This will require precision experiments with a very intense neutrino source. The future experiments such as T2K, NOVA and Double CHOOZ will measure the [Ue3] mixing. In order to explore CP violation, we present a novel method to create a monochromatic neutrino beam based on the recent discovery of nuclei that decay fast through electron capture in a superallowed Gamow-Teller transition. The boost of such radioactive ions will generate an intense monochromatic directional neutrino beam when decaying at high energy in a storage ring with long straight sections. We show that the capacity of such a facility to discover new physics is impressive, so that the principle of energy dependence in the oscillation probability of the suppressed {nu}e {yields} {nu}{mu} channel is operational to separate out the two parameters of the mixing {theta}13 and the CP-violating phase {delta}.},
doi = {10.1063/1.2563182},
journal = {AIP Conference Proceedings},
number = 1,
volume = 885,
place = {United States},
year = {Fri Feb 09 00:00:00 EST 2007},
month = {Fri Feb 09 00:00:00 EST 2007}
}
  • We have shown that nonzero U{sub e3} is generated in a seesaw type softly broken A{sub 4} symmetric model through a single parameter perturbation in m{sub D} in a single element. We have explored all possible 9 cases to study the neutrino mixing angles considering the best fitted values of {delta}m{sub {center_dot}}{sup 2} and {delta}m{sub atm}{sup 2} with all parameters real. We have extended our analysis for the complex case and demonstrated large low energy CP violation (J{sub CP}{approx_equal}10{sup -2}) and m{sub ee} in addition to mixing and mass pattern. We have also investigated leptogenesis and for a reasonable choicemore » of model parameters compatible with low energy data, the Wilkinson Microwave Anisotropy Probe (WMAP) value of baryon asymmetry 6x10{sup -10} is obtained for right-handed neutrino mass scale M{sub 0}{approx_equal}10{sup 13} GeV. We have obtained a relation among the phases responsible for leptogenesis and have shown that those phases also have correlations with low energy CP violating phases.« less
  • Is the relatively isolated member of the neutrino mass spectrum heavier or lighter than the two closely-spaced members? This question--the character of the neutrino mass hierarchy--is of great theoretical interest. All previously identified experiments for addressing it via neutrino oscillations require that the currently unknown size of the U{sub e3} element of the leptonic mixing matrix (parameterized by the unknown {theta}{sub 13} mixing angle) be sufficiently large, and will utterly fail in the limit {theta}{sub 13} {yields} 0. For this reason, we explore alternative oscillation approaches that would still succeed even if {theta}{sub 13} vanishes. We identify several alternatives thatmore » require neither a nonzero |U{sub e3}| nor the presence of significant matter effects. All include multiple percent-level neutrino oscillation measurements, usually involving muon-neutrino (or antineutrino) disappearance and very long baselines. We comment on the degree of promise that these alternative approaches show.« less
  • Is the relatively isolated member of the neutrino mass spectrum heavier or lighter than the two closely-spaced members? This question--the character of the neutrino mass hierarchy--is of great theoretical interest. All previously identified experiments for addressing it via neutrino oscillations require that the currently unknown size of the U{sub e3} element of the leptonic mixing matrix (parameterized by the unknown {theta}{sub 13} mixing angle) be sufficiently large, and will utterly fail in the limit {theta}{sub 13}{yields}0. For this reason, we explore alternative oscillation approaches that would still succeed even if {theta}{sub 13} vanishes. We identify several alternatives that require neithermore » a nonzero vertical bar U{sub e3} vertical bar nor the presence of significant matter effects (even if the latter are unavoidable in the case of long-baseline, Earth-based experiments). All include multiple percent-level neutrino oscillation measurements, usually involving muon-neutrino (or antineutrino) disappearance and very long baselines. We comment on the degree of promise that these alternative approaches show.« less
  • The neutrino mass hierarchy can be determined, in principle, by measuring a phase in the disappearance oscillation probability in vacuum, without relying on the matter effect, using a single channel. This phase is not the same for the normal and inverted neutrino mass spectra. In this paper, we give a complete description and physics understanding of the method. The key feature of the method is to detect advancement (normal) or retardation (inverted) of the phase of the atmospheric-scale oscillation relative to the solar-scale oscillation. We then show that this method can be realized with the recently proposed resonant {bar {nu}}emore » absorption reaction enhanced by the M{umlt o}ssbauer effect. The unique feature of this setup is the ultramonochromaticity of the observed {bar {nu}}e's. Because of this feature, the phase advancement or retardation of atmospheric-scale neutrino oscillation is detectable after 20 or more oscillations if the source and the target are made sufficiently compact in size. A quantitative estimate of the sensitivity to mass hierarchy resolution is given. We have also examined how a possible continuation of such an experiment can be carried out in order also to achieve high precision (few percent) determination of the solar-scale oscillation parameters Deltam212 and theta12.« less