28,387 research outputs found
Radiative Neutrino Mass, Dark Matter and Leptogenesis
We propose an extension of the standard model, in which neutrinos are Dirac
particles and their tiny masses originate from a one-loop radiative diagram.
The new fields required by the neutrino mass-generation also accommodate the
explanation for the matter-antimatter asymmetry and dark matter in the
universe.Comment: 4 pages, 3 figures. Revised version with improved model. Accepted by
PR
A left-right symmetric model with SU(2)-triplet fermions
We consider an
left-right symmetric model with three Higgs scalars including an
doublet, an doublet and an bidoublet. In
addition to usual SU(2)-doublet fermions, our model contains SU(2)-triplet
fermions with Majorana masses. The neutral components of the left-handed
triplets can contribute a canonical seesaw while the neutral components of the
right-handed triplets associated with the right-handed neutrinos can contribute
a double/inverse-type seesaw. Our model can be embedded into an SO(10) grand
unification theory where the triplets belong to the representations.Comment: 4 pages. To appear in Phys. Rev.
Neutrino masses, leptogenesis and dark matter in hybrid seesaw
We suggest a hybrid seesaw model where relatively ``light''right-handed
neutrinos give no contribution to the neutrino mass matrix due to a special
symmetry. This allows their Yukawa couplings to the standard model particles to
be relatively strong, so that the standard model Higgs boson can decay
dominantly to a left and a right-handed neutrino, leaving another stable
right-handed neutrino as cold dark matter. In our model neutrino masses arise
via the type-II seesaw mechanism, the Higgs triplet scalars being also
responsible for the generation of the matter-antimatter asymmetry via the
leptogenesis mechanism.Comment: 4 page
Radiative seesaw in left-right symmetric model
There are some radiative origins for the neutrino masses in the conventional
left-right symmetric models with the usual bi-doublet and triplet Higgs
scalars. These radiative contributions could dominate over the tree-level
seesaw and could explain the observed neutrino masses.Comment: 5 pages, 3 figures. Revised version with minor change. Accepted by
PR
Resonant Leptogenesis and Verifiable Seesaw from Large Extra Dimensions
In the presence of large extra dimensions, the fundamental scale could be as
low as a few TeV. This yields leptogenesis and seesaw at a TeV scale.
Phenomenologically two TeV-scale Majorana fermions with a small mass split can
realize a resonant leptogenesis whereas a TeV-scale Higgs triplet with a small
trilinear coupling to the standard model Higgs doublet can give a verifiable
seesaw. We propose an interesting scenario where the small parameters for the
resonant leptogenesis and the type-II seesaw can be simultaneously generated by
the propagation of lepton number violation from distant branes to our world.Comment: 5 pages. More discussions and references. Published in PR
Relations between Neutrino and Charged Fermion Masses
We find an intriguing relation between neutrino and charged fermion masses,
. We further indicate this
relation can be predicted by a left-right symmetric model.Comment: 4 pages, 1 figure. Model is slightly corrected. Title is changed.
Journal versio
- …