72 research outputs found
Interpreting the 750 GeV diphoton excess in minimal extensions of Two-Higgs-Doublet models
It is shown that the 750 GeV diphoton excess can be explained in extensions
of Two-Higgs-Doublet Models that do not involve large multiplicities of new
electromagnetically charged states. The key observation is that at moderate and
large the total decay width of the 750 GeV Higgs is strongly
reduced as compared to the Standard Model. This allows for much more economical
choices of new states that enhance the diphoton signal to fit the data. In
particular, it is shown that one family of vector-like quarks and leptons with
SM charges is enough to explain the 750 GeV diphoton excess. Moreover, such
charge assignment can keep the 125 GeV Higgs signal rates exactly at the SM
values. The scenario can interpret the diphoton excess provided that the total
decay width of a hypothetical resonance that would be measured at the LHC turns
out to not exceed few GeV.Comment: 11 pages, 4 figures; v2: fig.3, discussion of ditau constraints,
comments and references added; to appear in PL
Minimal Non-Abelian Supersymmetric Twin Higgs
We propose a minimal supersymmetric Twin Higgs model that can accommodate
tuning of the electroweak scale for heavy stops better than 10% with high
mediation scales of supersymmetry breaking. A crucial ingredient of this model
is a new SU(2)_X gauge symmetry which provides a D-term potential that
generates a large SU(4) invariant coupling for the Higgs sector and only small
set of particles charged under SU(2)_X, which allows the model to be
perturbative around the Planck scale. The new gauge interaction drives the top
yukawa coupling small at higher energy scales, which also reduces the tuning.Comment: 24 pages, 7 figures, matched to the published versio
Asymptotically Free Natural SUSY Twin Higgs
Twin Higgs (TH) models explain the absence of new colored particles
responsible for natural electroweak symmetry breaking (EWSB). All known
ultraviolet completions of TH models require some non-perturbative dynamics
below the Planck scale. We propose a supersymmetric model in which the TH
mechanism is introduced by a new asymptotically free gauge interaction. The
model features natural EWSB for squarks and gluino heavier than 2 TeV even if
supersymmetry breaking is mediated around the Planck scale, and has interesting
flavor phenomenology including the top quark decay into the Higgs and the up
quark which may be discovered at the LHC.Comment: 5 pages, 3 figure
Supersymmetric D-term Twin Higgs
We propose a new type of supersymmetric Twin Higgs model where the SU(4)
invariant quartic term is provided by a D-term potential of a new U(1) gauge
symmetry. In the model the 125 GeV Higgs mass can be obtained for stop masses
below 1 TeV, and a tuning required to obtain the correct electroweak scale can
be as low as 20 %. A stop mass of about 2 TeV is also possible with tuning of
order O(10) %.Comment: 27 pages, 5 figures; v2: appendix extended, matches version published
in JHE
New Regions in the NMSSM with a 125 GeV Higgs
It is pointed out that mixing effects in the CP-even scalar sector of the
NMSSM can give 6-8 GeV correction to the SM-like Higgs mass in moderate or
large regions with a small value of the singlet-higgs-higgs
superfields coupling . This effect comes mainly
from the mixing of the SM-like Higgs with lighter singlet. In the same
parameter range, the mixing of the heavy doublet Higgs with the singlet may
strongly modify the couplings of the singlet-like and the 125 GeV scalars.
Firstly, the LEP bounds on a light singlet can be evaded for a large range of
its masses. Secondly, the decay rates of both scalars can show a variety of
interesting patterns, depending on the lightest scalar mass. In particular, a
striking signature of this mechanism can be a light scalar with strongly
suppressed (enhanced) branching ratios to (, ,
) as compared to the SM Higgs with the same mass. The
decay channel is particularly promising for the search of such a
scalar at the LHC. The 125 GeV scalar can, thus, be accommodated with
substantially smaller than in the MSSM radiative corrections from the stop
loops (and consequently, with lighter stops) also for moderate or large
, with the mixing effects replacing the standard NMSSM mechanism of
increasing the tree level Higgs mass in the low and large
regime, and with clear experimental signatures of such a mechanism.Comment: 19 pages, 5 figures, references added, version to be publishe
- …