120 research outputs found
Pair production of 125 GeV Higgs boson in the SM extension with color-octet scalars at the LHC
Although the Higgs boson mass and single production rate have been determined
more or less precisely, its other properties may deviate significantly from its
predictions in the standard model (SM) due to the uncertainty of Higgs data. In
this work we study the Higgs pair production at the LHC in the Manohar-Wise
model, which extends the SM by one family of color-octet and isospin-doublet
scalars. We first scanned over the parameter space of the Manohar-Wise model
considering exprimental constraints and performed fits in the model to the
latest Higgs data by using the ATLAS and CMS data separately. Then we
calculated the Higgs pair production rate and investigated the potential of its
discovery at the LHC14. We conclude that: (i) Under current constrains
including Higgs data after Run I of the LHC, the cross section of Higgs pair
production in the Manohar-Wise model can be enhanced up to even times
prediction in the SM. (ii) Moreover, the sizable enhancement comes from the
contributions of the CP-odd color-octet scalar . For lighter scalar
and larger values of , the cross section of Higgs pair
production can be much larger. (iii) After running again of LHC at 14 TeV, most
of the parameter spaces in the Manohar-Wise model can be test. For an
integrated luminosity of 100 fb at the LHC14, when the normalized ratio
, the process of Higgs pair production can be detected.Comment: 13 pages, 4 figure
Higgs Phenomenology in the Minimal Dilaton Model after Run I of the LHC
The Minimal Dilaton Model (MDM) extends the Standard Model (SM) by a singlet
scalar, which can be viewed as a linear realization of general dilaton field.
This new scalar field mixes with the SM Higgs field to form two mass
eigenstates with one of them corresponding to the 125 GeV SM-like Higgs boson
reported by the LHC experiments. In this work, under various theoretical and
experimental constrains, we perform fits to the latest Higgs data and then
investigate the phenomenology of Higgs boson in both the heavy dilaton scenario
and the light dilaton scenario of the MDM. We find that: (i) If one considers
the ATLAS and CMS data separately, the MDM can explain each of them well, but
refer to different parameter space due to the apparent difference in the two
sets of data. If one considers the combined data of the LHC and Tevatron,
however, the explanation given by the MDM is not much better than the SM, and
the dilaton component in the 125-GeV Higgs is less than about 20% at 2 sigma
level. (ii) The current Higgs data have stronger constrains on the light
dilaton scenario than on the heavy dilaton scenario. (iii) The heavy dilaton
scenario can produce a Higgs triple self coupling much larger than the SM
value, and thus a significantly enhanced Higgs pair cross section at hadron
colliders. With a luminosity of 100 fb^{-1} (10 fb^{-1}) at the 14-TeV LHC, a
heavy dilaton of 400 GeV (500 GeV) can be examined. (iv) In the light dilaton
scenario, the Higgs exotic branching ratio can reach 43% (60%) at 2 sigma (3
sigma) level when considering only the CMS data, which may be detected at the
14-TeV LHC with a luminosity of 300 fb^{-1} and the Higgs Factory.Comment: 27 pages, 13 figures, discussions added, to appear in JHE
A light Higgs scalar in the NMSSM confronted with the latest LHC Higgs data
In the Next-to-Minimal Supersymemtric Standard Model (NMSSM), one of the
neutral Higgs scalars (CP-even or CP-odd) may be lighter than half of the
SM-like Higgs boson. In this case, the SM-like Higgs boson h can decay into
such a light scalar pair and consequently the diphoton and ZZ signal rates at
the LHC will be suppressed. In this work, we examine the constraints of the
latest LHC Higgs data on such a possibility. We perform a comprehensive scan
over the parameter space of the NMSSM by considering various experimental
constraints and find that the LHC Higgs data can readily constrain the
parameter space and the properties of the light scalar, e.g., at 3
level this light scalar should be highly singlet dominant and the branching
ratio of the SM-like Higgs boson decay into the scalar pair should be less than
about 30%. Also we investigate the detection of this scalar at various
colliders. Through a detailed Monte Carlo simulation we find that under the
constraints of the current Higgs data this light scalar can be accessible at
the LHC-14 with an integrated luminosity over 300 fb.Comment: Accepted by JHE
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