269 research outputs found
The solar neutrino puzzle: present situation and future scenarios
We present a short review of the existing evidence in favor of neutrino mass
and neutrino oscillations which come from different kinds of experiments. We
focus our attention in particular on solar neutrinos, presenting a global
updated phenomenological analysis of all the available data and we comment on
different possible future scenarios.Comment: 22 pp. Expanded version of the contribution to appear in the
Proceedings of ``Les Rencontres de Physique de la Vallee d'Aoste'', February
200
Solving the solar neutrino problem with kamLAND and BOREXINO
We analyze the expected signals of two future neutrino experiments, kamLAND
and BOREXINO. We show that with just these experiments, we will hopefully be
able to determine which of the existing solutions to the solar neutrino problem
is the real solution. We also analyze existing solar neutrino data and
determine the best-fit points in the oscillation-parameter space finding that
with the inclusion of SNO-charged current, the global-rates analysis gives a
favored LMA solution with a goodness of fit (g.o.f) of just 32.63%, whereas the
g.o.f of the SMA solution is 9.83%. Nonetheless, maximal and quasi-maximal
mixing is not favored. If we include the Superkamiokande spectrum in our \chi^2
analysis, we obtain a LMA solution with a g.o.f. of 84.38%.Comment: 4 pages, 5 figures, Talk given at 37th Rencontres de Moriond on
Electroweak Interactions and Unified Theories, Les Arcs, France, 9-16 Mar
200
After Sno and Before Kamland: Present and Future of Solar and Reactor Neutrino Physics
We present a short review of the existing evidence in favor of neutrino mass
and neutrino oscillations which come from different kinds of experiments. We
focus our attention in particular on solar neutrinos, presenting a review of
some recent analysis of all available neutrino oscillation evidence in Solar
experiments including the recent and data. We present in detail
the power of the reactor experiment KamLAND for discriminating existing
solutions to the SNP and giving accurate information on neutrino masses and
mixing angles.Comment: Expanded version of the contribution to appear in the Proceedings of
''Third Tropical Workshop on Particle Physics and Cosmology: Neutrinos,
Branes and Cosmology (Puerto Rico, August 2002)'
A model for fermion masses and lepton mixing in SO(10) x A4
The discrete flavor symmetry A4 explains very well neutrino data at low
energy, but it seems difficult to extend it to grand unified models since in
general left-handed and right-handed fields belong to different A4
representations. Recently it has been proposed a model where all the fermions
equally transform under A4. We study here a concrete SO(10) realization of such
a model providing small neutrino masses through the seesaw mechanism. We fit at
tree level the charged fermion masses run up to the unification scale. Some
fermion masses properties come from the SO(10) symmetry while lepton mixing
angles are consequence of the A4 properties. Moreover, our model predicts the
absolute value of the neutrino masses, these ones are in the range .Comment: 15 pages. V2: Final version to appear in the journa
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