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Title: Improved limit on {theta}{sub 13} and implications for neutrino masses in neutrinoless double beta decay and cosmology

Abstract

We analyze the impact of a measurement, or of an improved bound, on {theta}{sub 13} for the determination of the effective neutrino mass in neutrinoless double beta decay and cosmology. In particular, we discuss how an improved limit on (or a specific value of) {theta}{sub 13} can influence the determination of the neutrino mass spectrum via neutrinoless double beta decay. We also discuss the interplay with improved cosmological neutrino mass searches.

Authors:
; ;  [1]
  1. Physik-Department, Technische Universitaet Muenchen, James-Franck-Strasse, D-85748 Garching (Germany)
Publication Date:
OSTI Identifier:
20776840
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. D, Particles Fields; Journal Volume: 73; Journal Issue: 5; Other Information: DOI: 10.1103/PhysRevD.73.053005; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; COSMOLOGY; DOUBLE BETA DECAY; LIMITING VALUES; MASS SPECTRA; NEUTRINOS; REST MASS; STANDARD MODEL; WEINBERG ANGLE

Citation Formats

Lindner, Manfred, Merle, Alexander, and Rodejohann, Werner. Improved limit on {theta}{sub 13} and implications for neutrino masses in neutrinoless double beta decay and cosmology. United States: N. p., 2006. Web. doi:10.1103/PhysRevD.73.053005.
Lindner, Manfred, Merle, Alexander, & Rodejohann, Werner. Improved limit on {theta}{sub 13} and implications for neutrino masses in neutrinoless double beta decay and cosmology. United States. doi:10.1103/PhysRevD.73.053005.
Lindner, Manfred, Merle, Alexander, and Rodejohann, Werner. Wed . "Improved limit on {theta}{sub 13} and implications for neutrino masses in neutrinoless double beta decay and cosmology". United States. doi:10.1103/PhysRevD.73.053005.
@article{osti_20776840,
title = {Improved limit on {theta}{sub 13} and implications for neutrino masses in neutrinoless double beta decay and cosmology},
author = {Lindner, Manfred and Merle, Alexander and Rodejohann, Werner},
abstractNote = {We analyze the impact of a measurement, or of an improved bound, on {theta}{sub 13} for the determination of the effective neutrino mass in neutrinoless double beta decay and cosmology. In particular, we discuss how an improved limit on (or a specific value of) {theta}{sub 13} can influence the determination of the neutrino mass spectrum via neutrinoless double beta decay. We also discuss the interplay with improved cosmological neutrino mass searches.},
doi = {10.1103/PhysRevD.73.053005},
journal = {Physical Review. D, Particles Fields},
number = 5,
volume = 73,
place = {United States},
year = {Wed Mar 01 00:00:00 EST 2006},
month = {Wed Mar 01 00:00:00 EST 2006}
}
  • Neutrinoless double-beta decay is forbidden in the Standard Model of electroweak and strong interaction but allowed in most Grand Unified Theories (GUTs). Only if the neutrino is a Majorana particle (identical with its antiparticle) and if it has a mass is neutrinoless double-beta decay allowed. Apart from one claim that the neutrinoless double-beta decay in {sup 76}Ge is measured, one has only upper limits for this transition probability. But even the upper limits allow one to give upper limits for the electron Majorana neutrino mass and upper limits for parameters of GUTs and the minimal R-parity-violating supersymmetric model. One furthermore » can give lower limits for the vector boson mediating mainly the right-handed weak interaction and the heavy mainly right-handed Majorana neutrino in left-right symmetric GUTs. For that, one has to assume that the specific mechanism is the leading one for neutrinoless double-beta decay and one has to be able to calculate reliably the corresponding nuclear matrix elements. In the present work, one discusses the accuracy of the present status of calculating of the nuclear matrix elements and the corresponding limits of GUTs and supersymmetric parameters.« less
  • Neutrinoless double beta decay (0{nu}{beta}{beta}) is a promising test for lepton number violating physics beyond the standard model (SM) of particle physics. There is a deep connection between this decay and the phenomenon of neutrino masses. In particular, we will discuss the relation between 0{nu}{beta}{beta} and Majorana neutrino masses provided by the so-called Schechter-Valle theorem in a quantitative way. Furthermore, we will present an experimental cross check to discriminate 0{nu}{beta}{beta} from unknown nuclear background using only one isotope, i.e., within one experiment.
  • A lower limit of 1.16 x 10/sup 23/ yr (1sigma) is reported for the half-life of no-neutrino ..beta../sup -/..beta../sup -/ decay of /sup 76/Ge which results from 3763 h of counting with an ultralow-background, 135-cm/sup 3/ prototype detector located 1438 m underground. A limit of 1.7 x 10/sup 23/ yr (1sigma) results from the best combination of our data with that from other experiments. Straightforward application of shell-model matrix elements to this limit implies that <3.2 eV (1sigma).
  • We analyze the constraints on neutrino mass spectra with extra sterile neutrinos as implied by the LSND experiment. The various mass related observables in neutrinoless double beta decay, tritium beta decay and cosmology are discussed. Both neutrino oscillation results as well as recent cosmological neutrino mass bounds are taken into account. We find that some of the allowed mass patterns are severely restricted by the current constraints, in particular, by the cosmological constraints on the total sum of neutrino masses and by the nonmaximality of the solar neutrino mixing angle. Furthermore, we estimate the form of the four neutrino massmore » matrices and also comment on the situation in scenarios with two additional sterile neutrinos.« less
  • To realize the condition of sin{sup 2}2{theta}{sub 12}>>sin{sup 2}{theta}{sub 13}, we find constraints on flavor neutrino masses M{sub ij} (ij=e,{mu},{tau}): (C1) c{sub 23}{sup 2}M{sub {mu}}{sub {mu}}+s{sub 23}{sup 2}M{sub {tau}}{sub {tau}}{approx_equal}2s{sub 23}c{sub 23}M{sub {mu}}{sub {tau}}+M{sub ee} and/or (C2) vertical bar c{sub 23}M{sub e{mu}}-s{sub 23}M{sub e{tau}} vertical bar >> vertical bar s{sub 23}M{sub e{mu}}+c{sub 23}M{sub e{tau}} vertical bar, where c{sub 23}=cos{theta}{sub 23} (s{sub 23}=sin{theta}{sub 23}) and {theta}{sub 12}, {theta}{sub 13}, and {theta}{sub 23} are the mixing angles for three flavor neutrinos. The applicability of (C1) and (C2) is examined in models with one massless neutrino and two massive neutrinos suggested by det(M)=0,more » where M is a mass matrix constructed from M{sub ij} (i,j=e,{mu},{tau}). To make definite predictions on neutrino masses and mixings, especially on sin{theta}{sub 13}, that enable us to trace (C1) and (C2), M is assumed to possess texture zeros or to be constrained by textures with M{sub {mu}}{sub {mu}}=M{sub {tau}}{sub {tau}} or M{sub e{tau}}={+-}M{sub e{mu}}, which turn out to ensure the emergence of the maximal atmospheric neutrino mixing at sin{theta}{sub 13}{yields}0. It is found that (C1) is used by textures such as M{sub e{mu}}=0 or M{sub e{tau}}=0, while (C2) is used by textures such as M{sub e{tau}}={+-}M{sub e{mu}}.« less