9,213 research outputs found
Fermion mass hierarchy and new physics at the TeV scale
In this talk, I present a new framework to understand the long-standing
fermion mass hierarchy puzzle. We extend the Standard Model gauge symmetry by
an extra local U(1)_S symmetry, broken spontaneously at the electroweak scale.
All the SM particles are singlet with respect to this U(1)_S. We also introduce
additional flavor symmetries, U(1)_F's, with flavon scalars F_i, as well as
vectorlike quarks and leptons at the TeV scale. The flavon scalars have VEV in
the TeV scale. Only the top quark has the usual dimension four Yukawa coupling.
EW symmetry breaking to all other quarks and leptons are propagated through the
messenger field, S through their interactions involving the heavy vector-like
fermions and S, as well as through their interactions involving the vector-like
fermions and F_i. In addition the explaining the hierarchy of the charged
fermion masses and mixings, the model has several interesting predictions for
Higgs decays, flavor changing neutral current processes in the top and the b
quark decays, decays of the new singlet scalars to the new Z' boson, as well as
productions of the new vectorlike quarks. These predictions can be tested at
the LHC.Comment: 10 pages, 2 figures; Plenary talk presented at the 17th International
Conference on Supersymmetry and the Unification of Fundamental Interactions
(SUSY09) at Northeastern University, Boston, MA, 5-10 June, 200
Vector Galileon and inflationary magnetogenesis
Cosmological inflation provides the initial conditions for the structure
formation. However, the origin of large-scale magnetic fields cannot be
addressed in this framework. The key issue for this long-standing problem is
the conformal invariance of the electromagnetic (EM) field in 4-D. While many
approaches have been proposed in the literature for breaking conformal
invariance of the EM action, here, we provide a completely new way of looking
at the modifications to the EM action and generation of primordial magnetic
fields during inflation. We explicitly construct a higher derivative EM action
that breaks conformal invariance by demanding three conditions - theory be
described by vector potential and its derivatives, Gauge invariance be
satisfied, and equations of motion be linear in second derivatives of vector
potential. The unique feature of our model is that appreciable magnetic fields
are generated at small wavelengths while tiny magnetic fields are generated at
large wavelengths that are consistent with current observations.Comment: 20 pages, 0 figure, updated references, published in JCA
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