17 research outputs found
An SU(5)Z_{13} Grand Unification Model
We propose an SU(5) grand unified model with an invisible axion and the
unification of the three coupling constants which is in agreement with the
values, at , of , , and . A discrete,
anomalous, symmetry implies that the Peccei-Quinn symmetry is an
automatic symmetry of the classical Lagrangian protecting, at the same time,
the invisible axion against possible semi-classical gravity effects. Although
the unification scale is of the order of the Peccei-Quinn scale the proton is
stabilized by the fact that in this model the standard model fields form the
SU(5) multiplets completed by new exotic fields and, also, because it is
protected by the symmetry.Comment: 14 pages, more typos correcte
New fermions and a vector-like third generation in models
We study two 3-3-1 models with i) five (four) charge 2/3 () quarks and,
ii) four (five) charge 2/3 () quarks and a vector-like third generation.
Possibilities beyond these models are also briefly considered.Comment: 32 pages, Revtex 3.0, no figure
Neutrino physics and non-standard interactions
In most of the proposals for new physics beyond the standard model, neutrinos
have new interactions and some of them have phenomenological consequences that,
although at present they may seem purely academic, probably will have to be
taken into account in the future neutrino experiments. Here we show that new
interactions may imply the misidentification of the flavour of the neutrinos,
and the experimental ability to distinguish neutrinos from antineutrinos.Comment: 18 pages; New discussions and references adde