17,877 research outputs found
Diagnosing Degenerate Higgs Bosons at 125 GeV
We develop diagnostic tools that would provide incontrovertible evidence for
the presence of more than one Higgs boson near 125 GeV in the LHC data.Comment: 4 pages, 2 figure
Possible Explanation to Low CMB Quadrupole
The universe might experience many cycles with different vacua. The slow-roll
inflation may be preceded by kinetic-dominated contraction occurring in
"adjacent" vacua during some cycles. In this report we briefly show this
phenomenon may lead to a cutoff of primordial power spectrum. Thus in some
sense the CMB at large angular scale might encode the information of other
vacua.Comment: 10 pages, 3 eps figures, accepted for publication in PRD, v2 revised
with published versio
Two-Higgs-Doublet Models and Enhanced Rates for a 125 GeV Higgs
We examine the level of enhancement that can be achieved in the ZZ and
\gamma\gamma channels for a two-Higgs-doublet model Higgs boson (either the
light h or the heavy H) with mass near 125 GeV after imposing all constraints
from LEP data, B physics, precision electroweak data, vacuum stability,
unitarity and perturbativity. The latter constraints restrict substantially the
possibilities for enhancing the gg -> h -> \gamma\gamma or gg -> H ->
\gamma\gamma signal relative to that for the SM Higgs, hSM. Further, we find
that a significant enhancement of the gg -> h -> \gamma\gamma or gg -> H ->
\gamma\gamma signal in Type II models is possible only if the gg -> h -> ZZ or
gg -> H -> ZZ mode is even more enhanced, a situation disfavored by current
data. In contrast, in the Type I model one can achieve enhanced rates in the
\gamma\gamma final state for the h while having the ZZ mode at or below the SM
rate - the largest [gg -> h -> \gamma\gamma]/[gg -> hSM -> \gamma\gamma] ratio
found is of order ~1.3 when the two Higgs doublet vacuum expectation ratio is
tan\beta = 4 or 20 and the charged Higgs boson has its minimal LEP-allowed
value of m_{H^\pm} = 90 GeV.Comment: 15 pages, 9 figure
Isospin-violating dark-matter-nucleon scattering via two-Higgs-doublet-model portals
We show that in a multi-Higgs model in which one Higgs fits the LHC 125 GeV
state, one or more of the other Higgs bosons can mediate DM-nucleon
interactions with maximal DM isospin violation being possible for appropriate
Higgs-quark couplings, independent of the nature of DM. We then consider the
explicit example of a Type II two-Higgs-doublet model, identifying the h or H
as the 125 GeV state while the H or h, respectively, mediates DM-nucleon
interactions. Finally, we show that if a stable scalar, S, is added then it can
be a viable light DM candidate with correct relic density while obeying all
direct and indirect detection limits.Comment: Two subsections are added to address the collider bounds from direct
search for heavy Higgs bosons and from jet plus missing energy final states.
The LUX (2013) bound considered in the previous version is replaced by the
latest LUX (2016) bound and the SuperCDMS limit is taken into account. The
conclusions remain unchanged. A very minor change made in the title and new
references include
Radius stabilization and dark matter with a bulk Higgs in warped extra dimension
We employ an bulk Higgs doublet as the stabilization field in
Randall-Sundrum model with appropriate bulk and brane-localized potentials. The
gauge hierarchy problem can be solved for an exponentially IR-localized Higgs
background field with mild values of fundamental parameters of the 5D theory.
We consider an IR-UV-IR background geometry with the 5D SM fields in the bulk
such that all the fields have even and odd tower of KK-modes. The zero-mode 4D
effective theory contains all the SM fields plus a stable scalar, which serves
as a dark matter candidate.Comment: 8 pages, 4 figures. Talk given at the XXXIX International Conference
of Theoretical Physics "Matter To The Deepest", Ustron, Poland. Based on
arXiv:1504.0370
Higgs Dark Matter from a Warped Extra-Dimension -- the truncated-inert-doublet model
We construct a 5D -symmetric model with three D3-branes: two IR
ones with negative tension located at the ends of an extra-dimensional interval
and a UV-brane with positive tension placed in the middle of the interval --
IR-UV-IR model. The background solutions for this geometric setup are found
without and with taking into account the backreaction of the matter fields. A
5D Higgs doublet is employed as the Goldberger-Wise stabilizing field
in this geometry and solutions of the 5D coupled scalar-gravity equations are
found by using the superpotential method. Within this setup we investigate the
low-energy (zero-mode) effective theory for the bulk Standard Model (SM)
bosonic sector. The -even zero-modes correspond to known standard
degrees of freedom, whereas the -odd zero modes might serve as a
dark sector. The effective low-energy scalar sector contains a scalar which
mimics the SM Higgs boson and a second stable scalar particle (dark-Higgs) is a
dark matter candidate; the latter is a component of the zero-mode of the
-odd Higgs doublet. The model that results from the
-symmetric background geometry resembles the Inert Two Higgs
Doublet Model. The effective theory turns out to have an extra residual
global symmetry that is reminiscent of an underlying 5D
gauge transformation for the odd degrees of freedom. At tree level the SM Higgs
and the dark-Higgs have the same mass; however, when leading radiative
corrections are taken into account the dark-Higgs turns out to be heavier than
the SM Higgs. Implications for dark matter are discussed; it is found that the
dark-Higgs can provide only a small fraction of the observed dark matter
abundance.Comment: 38 pages, 8 figures and 2 tables. v2: a new subsection (2.2) on
radius stabilization with an SU(2) bulk Higgs doublet is added, which
provides exact analytic background solutions (with full backreaction) of the
Higgs-gravity 5D warped setup. References added, matches the version to
appear in JHE
Constraints on and future prospects for Two-Higgs-Doublet Models in light of the LHC Higgs signal
We analyze the Two-Higgs-Doublet Models (2HDMs) of Type I and II for
consistency with the latest measurements of the ~125.5 GeV Higgs-like signal at
the LHC. To this end, we perform scans of the 2HDM parameter space taking into
account all relevant pre-LHC constraints as well as the most recent limits
coming from searches for heavy Higgs-like states at the LHC. The current status
of the 2HDMs of Type I and II is discussed assuming that the observed 125.5 GeV
state is one of the two CP-even Higgs bosons, either the lighter h or the
heavier H. Implications for future experiments, including expectations
regarding other lighter or heavier Higgs bosons are given. The possible
importance of heavier Higgs bosons feeding the signals for the 125.5 GeV state
is also evaluated.Comment: 52 pages, 32 figures, match to the published versio
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