154 research outputs found
Anomalous Coupling in Double Higgs Production
We study the effects of top-Higgs anomalous coupling in the production of a
pair of Higgs boson via gluon fusion at the Large Hadron Collider (LHC). The
introduction of anomalous coupling can alter the hadronic double Higgs
boson cross section and can lead to characteristic changes in certain kinematic
distributions. We perform a global analysis based on available LHC data on the
Higgs to constrain the parameters of anomalous coupling. Possible overlap
of the predictions due to anomalous coupling with those due to anomalous
trilinear Higgs coupling is also studied. We briefly discuss the effect of the
anomalous coupling on the production via gluon fusion which is one
of the main backgrounds in the channel.Comment: 22 pages, 22 figures, 4 tables. Text reorganized, main results
unchanged, new plots and references added. Journal versio
Phenomenology of flavorful composite vector bosons in light of anomalies
We analyze the flavor structure of composite vector bosons arising in a model
of vectorlike technicolor, often called hypercolor (HC), with eight flavors
that form a one-family content of HC fermions. Dynamics of the composite vector
bosons, referred to as HC rho in this paper, are formulated together with HC
pions by the hidden local symmetry (HLS), in a way analogous to QCD vector
mesons. Then coupling properties to the standard model (SM) fermions, which
respect the HLS gauge symmetry, are described in a way that couplings of the HC
rhos to the left-handed SM quarks and leptons are given by a well-defined setup
as taking the flavor mixing structures into account. Under the present
scenario, we discuss significant bounds on the model from electroweak precision
tests, flavor physics, and collider physics. We also try to address B anomalies
in processes such as B -> K(*) mu+ mu- and B -> D(*) tau nu, recently reported
by LHCb, Belle, (ATLAS, and CMS in part.) Then we find that the present model
can account for the anomaly in B -> K(*) mu+ mu- consistently with the other
constraints while it predicts no significant deviations in B -> D(*) tau nu
from the SM, which can be examined in the future Belle II experiment. The
former is archived with the form C9 = -C10 of the Wilson coefficients for
effective operators of b -> s mu+ mu-, which has been favored by the recent
experimental data. We also investigate current and future experimental limits
at the Large Hadron Collider (LHC) and see that possible collider signals come
from dijet and ditau, or dimuon resonant searches for the present scenario with
TeV mass range. To conclude, the present b -> s mu+ mu- anomaly is likely to
imply discovery of new vector bosons in the ditau or dimuon channel in the
context of the HC rho model. Our model can be considered as a UV completion of
conventional U(1)' model.Comment: 62 pages, 8 figures, 3 tables, typos modified, published versio
CP-violating phase on magnetized toroidal orbifolds
We study the CP-violating phase of the quark sector in the flavor
model on with non-vanishing magnetic fluxes, where
properties of possible origins of the CP violation are investigated minutely.
In this system, a non-vanishing value is mandatory in the real part of the
complex modulus parameter of the two-dimensional torus. On without
orbifolding, underlying discrete flavor symmetries severely restrict the form
of Yukawa couplings and it is very difficult to reproduce the observed pattern
in the quark sector including the CP-violating phase . In
cases of multiple Higgs doublets emerging on , the mass matrices of
the zero-mode fermions can be written in the Gaussian textures by choosing
appropriate configurations of vacuum expectation values of the Higgs fields.
When such Gaussian textures of mass matrices are realized, we show that all of
the quark profiles, which are mass hierarchies among the quarks, quark mixing
angles, and can be simultaneously realized.Comment: 24 pages, 21 figures, 4 tables (v2, published version from JHEP
Seesaw mechanism in magnetic compactifications
In this paper, we explore a new avenue to a natural explanation of the
observed tiny neutrino masses with a dynamical realization of the
three-generation structure in the neutrino sector. Under the magnetized
background based on , matter consists of multiply-degenerated zero
modes and the whole intergenerational structure is dynamically determined. In
this sense, we can conclude that our scenario is favored by minimality, where
no degree of freedom remains to deform the intergenerational structure by hand
freely. Under the consideration of brane-localized Majorana-type mass terms for
an singlet neutrino, it is sufficient to introduce one Higgs doublet
for reproducing the observed neutrino data. In all reasonable flux
configurations with three right-handed neutrinos, phenomenologically acceptable
parameter configurations are found.Comment: 20 pages, 3 figures, 4 tables; published version from JHEP (v2
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