4 research outputs found
Seasonal Variations of the 7Be Solar Neutrino Flux
Measuring the 7Be solar neutrino flux is crucial towards solving the solar
neutrino puzzle. The Borexino experiment, and possibly the KamLAND experiment,
will be capable of studying the 7Be neutrinos in the near future. We discuss
(1) how the seasonal variation of the Borexino and KamLAND data can be used to
measure the 7Be solar neutrino flux in a background independent way and (2) how
anomalous seasonal variations might be used to discover vacuum neutrino
oscillations, independent of the solar model and the measurement of the
background. In particular, we find that, after three years of Borexino or
KamLAND running, vacuum neutrino oscillations can be either established or
excluded for almost all values of (sin^2 2 theta, Delta m^2) preferred by the
Homestake, GALLEX, SAGE, and Super-Kamiokande data. We also discuss how well
seasonal variations of the data can be used to measure (sin^2 2 theta, Delta
m^2) in the case of vacuum oscillations.Comment: 39 pages, 13 figures, uses psfig. Now the impact of the MSW effect on
vacuum oscillations taken into account. Conclusions unchanged. References
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Composite model with neutrino large mixing
We suggest a simple composite model that induces the large flavor mixing of
neutrino in the supersymmetric theory. This model has only one hyper-color in
addition to the standard gauge group, which makes composite states of preons.
In this model, {\bf 10} and {\bf 1} representations in SU(5) grand unified
theory are composite states and produce the mass hierarchy. This explains why
the large mixing is realized in the lepton sector, while the small mixing is
realized in the quark sector. This model can naturally solve the atmospheric
neutrino problem. We can also solve the solar neutrino problem by improving the
model.Comment: 20 pages, Latex, no figure
Construction of an SO(10) x U(1)_F Model of the Yukawa Interactions
We construct a supersymmetric model of the Yukawa
interactions at the grand unification scale from knowledge of a
phenomenological set of mass matrices obtained by a previous bottom-up
approach. The family symmetry determines the textures for the Majorana
and generic Dirac mass matrices, while the symmetry relates each
particular element of the up, down, neutrino and charged lepton Dirac matrices.
The dominant second and third family contributions in the Dirac sector are
renormalizable, while the remaining contributions to the Dirac mass matrices
are of higher order, restricted by the family symmetry to a small set
of tree diagrams, and mainly complex-symmetric. The tree diagrams for the
Majorana mass matrix are all non-renormalizable and of progressively
higher-order, leading to a nearly geometrical structure. Pairs of and Higgs representations enter with those having large vacuum
expectation values breaking the symmetry down to near the grand unification scale. In terms of 12 parameters expressed
as the Yukawa couplings times vacuum expectation values for the Higgs
representations employed, a realistic set of 15 quark and lepton masses
(including those for the 3 heavy righthanded Majorana neutrinos) and 8 mixing
parameters emerges for the neutrino scenario involving the non-adiabatic
conversion of solar neutrinos and the depletion of atmospheric muon-neutrinos
through oscillations into tau-neutrinos.Comment: 32 pages, latex with style files attached, 1 figure in uuencoded
postscript fil