53 research outputs found
The economical 3-3-1 model revisited
We show that the economical 3-3-1 model poses a very high new physics scale
of the order of 1000~TeV due to the constraint on the flavor-changing neutral
current. The implications of the model for neutrino masses, inflation,
leptogenesis, and superheavy dark matter are newly recognized. Alternatively,
we modify the model by rearranging the third quark generation differently from
the first two quark generations, as well as changing the scalar sector. The
resultant model now predicts a consistent new physics at TeV scale unlike the
previous case and may be fully probed at the current colliders. Particularly,
due to the minimal particle contents, the models under consideration manifestly
accommodate dark matter candidates and neutrino masses, with novel and distinct
production mechanisms. The large flavor-changing neutral currents that come
from the ordinary and exotic quark mixings can be avoided due to the
approximate symmetry.Comment: 21 pages; english writing improved, dark matter stability stated, and
references added; matches journal versio
The 3-3-1 model with A_4 flavor symmetry
We argue that the A_4 symmetry as required by three flavors of fermions may
well-embed in the SU(3)_C X SU(3)_L X U(1)_X gauge model. The new neutral
fermion singlets as introduced in a canonical seesaw mechanism can be combined
with the standard model lepton doublets to perform SU(3)_L triplets. Various
leptoscalar multiplets such as singlets, doublets, and triplets as played in
the models of A_4 are unified in single SU(3)_L antisextets. As a result,
naturally light neutrinos with various kinds of mass hierarchies are obtained
as a combination of type I and type II seesaw contributions. The observed
neutrino mixing pattern in terms of the Harrison-Perkins-Scott proposal is
obtained by enforcing of the A_4 group. The quark masses and
Cabibbo-Kobayashi-Maskawa mixing matrix are also discussed. By virtue of very
heavy antisextets the nature of the vacuum alignments of scalar fields can be
given.Comment: Version published by PR
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