23 research outputs found
Invisible decays of ultra-high energy neutrinos
Gamma-ray bursts (GRBs) are expected to provide a source of ultra high energy
cosmic rays, accompanied with potentially detectable neutrinos at neutrino
telescopes. Recently, IceCube has set an upper bound on this neutrino flux well
below theoretical expectation. We investigate whether this mismatch between
expectation and observation can be due to neutrino decay. We demosntrate the
phenomenological consistency and theoretical plausibility of the neutrino decay
hypothesis. A potential implication is the observability of majoron-emitting
neutrinoless double beta decay.Comment: 11 pages, 3 figures. To appear in Frontiers High Energy Physic
A new neutrino mass sum rule from inverse seesaw
A class of discrete flavor-symmetry-based models predicts constrained
neutrino mass matrix schemes that lead to specific neutrino mass sum-rules
(MSR). One of these implies in a lower bound on the effective neutrinoless
double beta mass parameter, even for normal hierarchy neutrinos. Here we
propose a new model based on the S4 flavor symmetry that leads to the new
neutrino mass sum-rule and discuss how to generate a nonzero value for the
reactor mixing angle indicated by recent experiments, and the resulting
correlation with the solar mixing angle.Comment: 14 pages, 4 figure
Neutrino-less Double Beta Decay and Particle Physics
We review the particle physics aspects of neutrino-less double beta decay.
This process can be mediated by light massive Majorana neutrinos (standard
interpretation) or by something else (non-standard interpretations). The
physics potential of both interpretations is summarized and the consequences of
future measurements or improved limits on the half-life of neutrino-less double
beta decay are discussed. We try to cover all proposed alternative realizations
of the decay, including light sterile neutrinos, supersymmetric or left-right
symmetric theories, Majorons, and other exotic possibilities. Ways to
distinguish the mechanisms from one another are discussed. Experimental and
nuclear physics aspects are also briefly touched, alternative processes to
double beta decay are discussed, and an extensive list of references is
provided.Comment: 96 pages, 38 figures. Published versio
Accidental stability of dark matter
We propose that dark matter is stable as a consequence of an accidental Z2
that results from a flavour-symmetry group which is the double-cover group of
the symmetry group of one of the regular geometric solids. Although
model-dependent, the phenomenology resembles that of a generic Higgs portal
dark matter scheme.Comment: 12 pages, final version, published in JHE
Constraining neutrinoless double beta decay
A class of discrete flavor-symmetry-based models predicts constrained
neutrino mass matrix schemes that lead to specific neutrino mass sum-rules
(MSR). We show how these theories may constrain the absolute scale of neutrino
mass, leading in most of the cases to a lower bound on the neutrinoless double
beta decay effective amplitude.Comment: 12 pages, 12 figure