254 research outputs found
Lepton-portal Dark Matter in Hidden Valley model and the DAMPE recent results
We study the recent cosmic ray excess reported by DAMPE in a Hidden
Valley Model with lepton-portal dark matter. We find the electron-portal can
account for the excess well and satisfy the DM relic density and direct
detection bounds, while electron+muon/electron+muon+tau-portal suffers from
strong constraints from lepton flavor violating observables, such as . We also discuss possible collider signatures of our model, both at the LHC
and a future 100 TeV hadron collider.Comment: invited by Science China, accepted versio
Single top partner production in the Higgs to diphoton channel in the Littlest Higgs Model with -parity
The top partner as a hallmark of the Littlest Higgs model with -parity
(LHT model) has been extensively searched for during the Large Hadron Collider
(LHC) Run-1. With the increasing mass limits on the top partner, the single
production of the top partner will be dominant over the pair production. Under
the constraints from the Higgs data, the electroweak precision observables and
, we find that the mass of -even top partner () has to be heavier
than 730 GeV. Then, we investigate the observability of the single -even top
partner production through the process with the sequent decay
in the di-photon channel in the LHT model at the LHC. We find that
the mass of can be excluded up to 800 GeV at level at 14 TeV
LHC with the integrated luminosity ab
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
Higgs self-coupling in the MSSM and NMSSM after the LHC Run 1
Measuring the Higgs self-coupling is one of the crucial physics goals at the
LHC Run-2 and other future colliders. In this work, we attempt to figure out
the size of SUSY effects on the trilinear self-coupling of the 125 GeV Higgs
boson in the MSSM and NMSSM after the LHC Run-1. Taking account of current
experimental constraints, such as the Higgs data, flavor constraints,
electroweak precision observables and dark matter detections, we obtain the
observations: (1) In the MSSM, the ratio of
has been tightly constrained by the LHC
data, which can be only slightly smaller than 1 and minimally reach 97\%; (2)
In the NMSSM with , a sizable reduction of
can occur and minimally reach 10\%
when the lightest CP-even Higgs boson mass is close to the SM-like
Higgs boson due to the large mixing angle between the singlet and
doublet Higgs bosons; (3) In the NMSSM with , a large enhancement
or reduction can occur,
which is accompanied by a sizable change of coupling. The
future colliders, such as the HL-LHC and ILC, will have the capacity to test
these large deviations in the NMSSM.Comment: 28 pages, discussions and references added, matched to journal
versio
750 GeV Diphoton Resonance, 125 GeV Higgs and Muon g-2 Anomaly in Deflected Anomaly Mediation SUSY Breaking Scenario
We propose to interpret the 750 GeV diphoton excess in deflected anomaly
mediation supersymmetry breaking scenarios, which can naturally predict
couplings between a singlet field and vector-like messengers. The CP-even
scalar component (S) of the singlet field can serve as the 750 GeV resonance.
The messenger scale, which is of order the gravitino scale, can be as light as
F_\phi \sim {\cal O}(10) TeV when the messenger species N_F and the deflection
parameter d are moderately large. Such messengers can induce the large loop
decay process S \to \gamma\gamma. Our results show that such a scenario can
successfully accommodate the 125 GeV Higgs boson, the 750 GeV diphoton excess
and the muon g-2 without conflicting with the LHC constraints. We also comment
on the possible explanations in the gauge mediation supersymmetry breaking
scenario.Comment: Published version in PLB; 15 pages,2 figure
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