40 research outputs found
Improving LMA predictions with non standard interactions
It has been known for some time that the well established LMA solution to the
observed solar neutrino deficit fails to predict a flat energy spectrum for
SuperKamiokande as opposed to what the data indicates. It also leads to a
Chlorine rate which appears to be too high as compared to the data. We
investigate the possible solution to these inconsistencies with non standard
neutrino interactions, assuming that they come as extra contributions to the
and vertices that affect both the
propagation of neutrinos through solar matter and their detection. We find
that, among the many possibilities for non standard couplings, only one of them
leads to a flat SuperKamiokande spectral rate in better agreement with the data
and predicts a Chlorine rate within 1 of the observed one, while
keeping all other predictions accurate
Improving LMA predictions with non-standard interactions: neutrino decay in solar matter?
It has been known for some time that the well established LMA solution to the
observed solar neutrino deficit fails to predict a flat energy spectrum for
SuperKamiokande as opposed to what the data indicates. It also leads to a
Chlorine rate which appears to be too high as compared to the data. We
investigate the possible solution to these inconsistencies with non standard
neutrino interactions, assuming that they come as extra contributions to the
and vertices that affect both the
propagation of neutrinos in the sun and their detection. We find that, among
the many possibilities for non standard couplings, only the diagonal imaginary
ones lead to a solution to the tension between the LMA predictions and the
data, implying neutrino instability in the solar matter. Unitarity requirements
further restrict the solution and a neutrino decay into an antineutrino and a
majoron within the sun is the one favoured. Antineutrino probability is however
too small to open the possibility of experimentally observing antineutrinos
from the sun due to NSI.Comment: 27 pages, 8 figures. Final version to be published in Physical Review
Neutrino Mass Matrices with Vanishing Determinant and
We investigate the prospects for scenarios with vanishing determinant
neutrino mass matrices and vanishing mixing angle. Normal and
inverse mass hierarchies are considered separately. For normal hierarchy it is
found that neutrinoless double beta decay cannot be observed by any of the
present or next generation experiments. For inverse hierarchy the neutrinoless
double beta decay is, on the contrary, accessible to experiments. We also
analyse for both hierarchies the case for texture zeros and equalities between
mass matrix elements. No texture zeros are found to be possible nor any such
equalities, apart from the obvious ones.Comment: 14 pages, 1 figur