10,274 research outputs found
Fundamental Composite 2HDM: SU(N) with 4 flavours
We present a new model of composite Higgs based on a gauged SU(N) group with
4 Dirac fermions in the fundamental representation. At low energy, the model
has a global symmetry SU(4)SU(4) broken to the diagonal SU(4),
containing 2 Higgs doublets in the coset. We study in detail the generation of
the top mass via 4-fermion interactions, and the issue of the vacuum alignment.
In particular, we prove that, without loss of generality, the vacuum can always
be aligned with one doublet. Under certain conditions on the top pre-Yukawas,
the second doublet, together with the additional triplets, is stable and can
thus play the role of Dark Matter. This model can therefore be an example of
composite inert-2HDM model.Comment: 34 pages, 2 figure
Doubly Charged Lepton from an Exotic Doublet at the LHC
We studied the signatures at the LHC of the electroweak SU(2) lepton doublet
which embeds a doubly charged lepton. The doubly charged lepton pair and single
production rates, which are different from the triplet case, are studied and
all the detectable decay modes are considered. We also applied the same
kinematic cuts as in triplet case to reduce the background at LHC and the
needed integrated luminosities to find the doubly charged leptons with
different masses are analyzed. We also suggested a method to distinguish the
exotic lepton doublet and triplet.Comment: 21 pages, 12 figure
Triplet with a doubly-charged lepton at the LHC
We studied the signatures of an electroweak SU(2) lepton triplet which
contains a doubly charged heavy lepton. The most interesting and easily
detected final states are originating from the doubly charged lepton pair and
single production, that we analyzed at a center of mass energy of 14 TeV. We
propose useful kinematic cuts to reduce the backgrounds and computed the
integrated luminosity needed to discover or exclude the doubly charged leptons
for various masses.Comment: 26 pages, 13 figures. arXiv admin note: text overlap with
arXiv:1105.5417 by other author
Composite Dark Matter and Higgs
We investigate the possibility that Dark Matter arises as a composite state
of a fundamental confining dynamics, together with the Higgs boson. We focus on
the minimal SU(4)SU(4)/SU(4) model which has both a Dark Matter and a
Higgs candidates arising as pseudo-Nambu-Goldstone bosons. At the same time, a
simple underlying gauge-fermion theory can be defined providing an existence
proof of, and useful constraints on, the effective field theory description. We
focus on the parameter space where the Dark Matter candidate is mostly a gauge
singlet. We present a complete calculation of its relic abundance and find
preferred masses between 500 GeV to a few TeV. Direct Dark Matter detection
already probes part of the parameter space, ruling out masses above 1 TeV,
while Indirect Detection is relevant only if non-thermal production is assumed.
The prospects for detection of the odd composite scalars at the LHC are also
established.Comment: 54 pages, 10 figures; Typo fixed, figures improved, refs added et
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