9,826 research outputs found
Study of the heavy CP-even Higgs with mass 125 GeV in two-Higgs-doublet models at the LHC and ILC
We assume that the 125 GeV Higgs discovered at the LHC is the heavy CP-even
Higgs of the two-Higgs-doublet models, and examine the parameter space in the
Type-I, Type-II, Lepton-specific and Flipped models allowed by the latest Higgs
signal data, the relevant experimental and theoretical constraints. Further, we
show the projected limits on , , and
couplings from the future measurements of the 125 GeV Higgs at the LHC
and ILC, including the LHC with integrated luminosity of 300 fb (LHC-300
fb) and 3000 fb (LHC-3000 fb) as well as the ILC at
GeV (ILC-250 GeV), GeV (ILC-500 GeV) and
GeV (ILC-1000 GeV). Assuming that the future Higgs signal data
have no deviation from the SM expectation, the LHC-300 fb, LHC-3000
fb and ILC-1000 GeV can exclude the wrong-sign Yukawa coupling regions
of the Type-II, Flipped and Lepton-specific models at the level,
respectively. The future experiments at the LHC and ILC will constrain the
Higgs couplings to be very close to SM values, especially for the
coupling.Comment: 22 pages, 3 tables, 6 figures. Version accepted for publication in
JHE
A simplified 2HDM with a scalar dark matter and the galactic center gamma-ray excess
Due to the strong constrain from the LUX experiment, the scalar portal dark
matter can not generally explain a gamma-ray excess in the galactic center by
the annihilation of dark matter into . With the motivation of
eliminating the tension, we add a scalar dark matter to the aligned
two-Higgs-doublet model, and focus on a simplified scenario, which has two main
characteristics: (i) The heavy CP-even Higgs is the discovered 125 GeV Higgs
boson, which has the same couplings to the gauge bosons and fermions as the SM
Higgs. (ii) Only the light CP-even Higgs mediates the dark matter interactions
with SM particles, which has no couplings to and , but the independent
couplings to the up-type quarks, down-type quarks and charged leptons. We find
that the tension between and the constraint from
LUX induced by the scalar portal dark matter can go away for the
isospin-violating dark matter-nucleon coupling with , and
the constraints from the Higgs search experiments and the relic density of
Planck are also satisfied.Comment: 12 pages, 3 figures, 1 table; reference adde
Status of the aligned two-Higgs-doublet model confronted with the Higgs data
Imposing the theoretical constraints from vacuum stability, unitarity and
perturbativity as well as the experimental constraints from the electroweak
precision data, flavor observables and the non-observation of additional Higgs
at collider, we study the implications of available Higgs signals on a
two-Higgs-doublet model with the alignment of the down-type quarks and charged
lepton Yukawa coupling matrices. Compared to the four traditional types of
two-Higgs-doublet models, the model has two additional mixing angles
and in the down-type quark and charged lepton Yukawa interactions.
We find that the mixing angle can loose the constraints on
, and sizably. The model can
provide the marginally better fit to available Higgs signals data than SM,
which requires the Higgs couplings with gauge bosons, and
to be properly suppressed, and favors (1 <\theta_d< 2, 0.5 <\theta_l< 2.2) for
125.5 GeV and (0.5 <\theta_d< 2, 0.5 <\theta_l< 2.2) for 125.5
GeV. However, these Higgs couplings are allowed to have sizable deviations from
SM for ( 125.5 GeV, 125.5 128 GeV) and (125 GeV 125.5 GeV, 125.5 GeV).Comment: 21 pages, 9 figures and 3 tables. Final version appeared in JHE
LHC diphoton and Z+photon Higgs signals in the Higgs triplet model with Y=0
We study the implications of the LHC diphoton and Z+photon Higgs signals on
the Higgs triplet model with Y=0. We discuss three different scenarios: (i) the
observed boson is the light Higgs boson ; (ii) it is the heavy Higgs boson
; (iii) the observed signal is from the almost degenerate and . We
find that the inclusive Higgs diphoton rates in the first two scenarios can be
enhanced or suppressed compared to the SM value, which can respectively fit the
ATLAS and CMS diphoton data within range. The inclusive rates
are suppressed, which are outside range of ATLAS data and within
range of CMS data. Meanwhile, another CP-even Higgs boson production
rate can be suppressed enough not to be observed at the collider. For the third
scenario, the Higgs diphoton rate is suppressed, which is outside
range of ATLAS data, and the rate equals to SM value approximately. In
addition, we find that the two rates of and
have the positive correlations for the three scenarios.Comment: 16 pages, 8 figures. Update of Higgs data, references added. Final
version appeared in JHE
130 GeV gamma-ray line and enhancement of in the Higgs triplet model plus a scalar dark matter
With a discrete symmetry being imposed, we introduce a real singlet
scalar to the Higgs triplet model with the motivation of explaining the
tentative evidence for a spectral feature at = 130 GeV in the Fermi
LAT data. The model can naturally satisfy the experimental constraints of the
dark matter relic density and direct detection data from Xenon100. The doubly
charged and one charged scalars can enhance the annihilation cross section of
via the one-loop contributions, and give the negligible
contributions to the relic density. for
GeV can reach \ord(1)\times10^{-27} cm^3 s^{-1} for the small
charged scalar masses and the coupling constant of larger than 1. Besides, this
model also predict a second photon peak at 114 GeV from the annihilation
, and the cross section is approximately 0.76 times that of
, which is below the upper limit reported by Fermi LAT.
Finally, the light charged scalars can enhance LHC diphoton Higgs rate, and
make it to be consistent with the experimental data reported by ATLAS and CMS.Comment: 15 pages, 4 figure
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