11 research outputs found
Large Solar Neutrino Mixing in an Extended Zee Model
The Zee model, which employs the standard Higgs scalar () with its
duplicate () and a singly charged scalar (), can utilize two
global symmetries associated with the conservation of the numbers of and
, , where coincides
with the hypercharge while () is a new
conserved charge, which is identical to for the left-handed
leptons. Charged leptons turn out to have - and - mixing
masses, which are found to be crucial for the large solar neutrino mixing. In
an extended version of the Zee model with an extra triplet Higgs scalar (s),
neutrino oscillations are described by three steps: 1) the maximal atmospheric
mixing is induced by democratic mass terms supplied by with =2 that can
initiate the type II seesaw mechanism for the smallness of these masses; 2) the
maximal solar neutrino mixing is triggered by the creation of radiative masses
by with = 0; 3) the large solar neutrino mixing is finally induced by
a - mixing arising from the rotation of the radiative mass
terms as a result of the diagonalization that converts - and -
mixing masses into the electron mass.Comment: RevTex, 10 pages including one figure page, to be published in Int.
J. Mod. Phys. A (2002
Fake CPT Violation in Disappearance Neutrino Oscillations
We make an analysis of the fake CPT-violating asymmetries between the
survival probabilities of neutrinos and antineutrinos, induced by the
terrestrial matter effects, in three different scenarios of long-baseline
neutrino oscillation experiments with L=730 km, L=2100 km and L=3200 km. In
particular, the dependence of those asymmetries on the Dirac-type CP-violating
phase of the lepton flavor mixing matrix is examined.Comment: RevTex 8 pages (including 3 PS figures). To be publishe
Quantum Isometries of the finite noncommutative geometry of the Standard Model
We compute the quantum isometry group of the finite noncommutative geometry F
describing the internal degrees of freedom in the Standard Model of particle
physics. We show that this provides genuine quantum symmetries of the spectral
triple corresponding to M x F where M is a compact spin manifold. We also prove
that the bosonic and fermionic part of the spectral action are preserved by
these symmetries.Comment: 29 pages, no figures v3: minor change
Lepton Number Violation in TeV Scale See-Saw Extensions of the Standard Model
The low-energy neutrino physics constraints on the TeV scale type I see-saw
scenarios of neutrino mass generation are revisited. It is shown that lepton
charge (L) violation, associated to the production and decays of heavy Majorana
neutrinos N_{j} having masses in the range of M_j \sim (100 \div 1000) GeV and
present in such scenarios, is hardly to be observed at ongoing and future
particle accelerator experiments, LHC included, because of very strong
constraints on the parameters and couplings responsible for the corresponding
|\Delta L| = 2 processes. If the heavy Majorana neutrinos N_j are observed and
they are associated only with the type I mechanism, they will behave
effectively like pseudo-Dirac fermions. Conversely, the observation of effects
proving the Majorana nature of N_j would imply that these heavy neutrinos have
additional relatively strong couplings to the Standard Model particles or that
light neutrino masses compatible with the observations are generated by a
mechanism other than see-saw (e.g., radiatively at one or two loop level) in
which the heavy Majorana neutrinos N_j are nevertheless involved.Comment: Contribution to the Proceedings of DISCRETE 2010- Symposium on
Prospects in the Physics of Discrete Symmetries, 8 page
Measurement of the nu(e) and total B-8 solar neutrino fluxes with the Sudbury neutrino observatory phase I data set
No description supplie
Neutrino oscillations: status, prospects and opportunities at a neutrino factory
We review the current status of neutrino oscillations after 1258 days of Super-Kamiokande, assess their future prospects over the next 10 years as the next generation of experiments come on-line, and discuss the longer-term opportunities presented by a neutrino factory. We also give an introduction to the see-saw mechanism and its application to atmospheric and solar neutrinos