71 research outputs found
MSSM A-funnel and the Galactic Center Excess: Prospects for the LHC and Direct Detection Experiments
The pseudoscalar resonance or "A-funnel" in the Minimal Supersymmetric
Standard Model~(MSSM) is a widely studied framework for explaining dark matter
that can yield interesting indirect detection and collider signals. The
well-known Galactic Center excess (GCE) at GeV energies in the gamma ray
spectrum, consistent with annihilation of a GeV dark matter
particle, has more recently been shown to be compatible with significantly
heavier masses following reanalysis of the background. In this paper, we
explore the LHC and direct detection implications of interpreting the GCE in
this extended mass window within the MSSM A-funnel framework. We find that
compatibility with relic density, signal strength, collider constraints, and
Higgs data can be simultaneously achieved with appropriate parameter choices.
The compatible regions give very sharp predictions of 200-600 GeV CP-odd/even
Higgs bosons at low tan at the LHC and spin-independent cross sections
pb at direct detection experiments. Regardless of
consistency with the GCE, this study serves as a useful template of the strong
correlations between indirect, direct, and LHC signatures of the MSSM A-funnel
region.Comment: 32 pages and 9 figure
Indirect Probes of the MSSM after the Higgs Discovery
We study the minimal supersymmetric standard model (MSSM) with minimal flavor
violation (MFV), imposing constraints from flavor physics observables and MSSM
Higgs searches, in light of the recent discovery of a 125 GeV Higgs boson by
ATLAS and CMS. We analyze the electroweak vacuum stability conditions to
further restrict the MSSM parameter space. In addition, a connection to
ultraviolet physics is shown via an implementation of renormalization group
running, which determines the TeV-scale spectrum from a small set of minimal
supergravity parameters. Finally, we investigate the impact from dark matter
direct detection searches. Our work highlights the complementarity of collider,
flavor and dark matter probes in exploring the MSSM, and shows that even in a
MFV framework, flavor observables constrain the MSSM parameter space well
beyond the current reach of direct SUSY particle searches.Comment: 28 pages, 15 figures; v2, updated with new LHCb and direct A->tau tau
results from HCP 2012, references adde
Two Higgs Doublets and a Complex Singlet: Disentangling the Decay Topologies and Associated Phenomenology
We present a systematic study of an extension of the Standard Model (SM) with
two Higgs doublets and one complex singlet (2HDM+S). In order to gain
analytical understanding of the parameter space, we re-parameterize the 27
parameters in the Lagrangian by quantities more closely related to physical
observables: physical masses, mixing angles, trilinear and quadratic couplings,
and vacuum expectation values. Embedding the 125\,GeV SM-like Higgs boson
observed at the LHC places stringent constraints on the parameter space. In
particular, the mixing of the SM-like interaction state with the remaining
states is severely constrained, requiring approximate alignment without
decoupling in the region of parameter space where the additional Higgs bosons
are light enough to be accessible at the LHC. In contrast to 2HDM models, large
branching ratios of the heavy Higgs bosons into two lighter Higgs bosons or a
light Higgs and a boson, so-called Higgs cascade decays, are ubiquitous in
the 2HDM+S. Using currently available limits, future projections, and our own
collider simulations, we show that combining different final states arising
from Higgs cascades would allow to probe most of the interesting region of
parameter space with Higgs boson masses up to 1\,TeV at the LHC with
of data.Comment: 43 pages, 7 figures, 2 tables. v2: matches published versio
Higgs Portals for Thermal Dark Matter - EFT Perspectives and the NMSSM -
We analyze a low energy effective model of Dark Matter in which the thermal
relic density is provided by a singlet Majorana fermion which interacts with
the Higgs fields via higher dimensional operators. Direct detection signatures
may be reduced if blind spot solutions exist, which naturally appear in models
with extended Higgs sectors. Explicit mass terms for the Majorana fermion can
be forbidden by a symmetry, which in addition leads to a reduction of the
number of higher dimensional operators. Moreover, a weak scale mass for the
Majorana fermion is naturally obtained from the vacuum expectation value of a
scalar singlet field. The proper relic density may be obtained by the
-channel interchange of Higgs and gauge bosons, with the longitudinal mode
of the boson (the neutral Goldstone mode) playing a relevant role in the
annihilation process. This model shares many properties with the
Next-to-Minimal Supersymmetric extension of the Standard Model (NMSSM) with
light singlinos and heavy scalar and gauge superpartners. In order to test the
validity of the low energy effective field theory, we compare its predictions
with those of the ultraviolet complete NMSSM. Extending our framework to
include neutral Majorana fermions, analogous to the bino in the NMSSM, we
find the appearance of a new bino-singlino well tempered Dark Matter region.Comment: 42 pages, 14 figures. v2: added references, published in JHE
Impersonating the Standard Model Higgs Boson: Alignment without Decoupling
In models with an extended Higgs sector there exists an alignment limit, in
which the lightest CP-even Higgs boson mimics the Standard Model Higgs. The
alignment limit is commonly associated with the decoupling limit, where all
non-standard scalars are significantly heavier than the boson. However,
alignment can occur irrespective of the mass scale of the rest of the Higgs
sector. In this work we discuss the general conditions that lead to "alignment
without decoupling", therefore allowing for the existence of additional
non-standard Higgs bosons at the weak scale. The values of for
which this happens are derived in terms of the effective Higgs quartic
couplings in general two-Higgs-doublet models as well as in supersymmetric
theories, including the MSSM and the NMSSM. Moreover, we study the information
encoded in the variations of the SM Higgs-fermion couplings to explore regions
in the parameter space.Comment: 42 Pages, 8 figure
Closing the Wedge: Search Strategies for Extended Higgs Sectors with Heavy Flavor Final States
We consider search strategies for an extended Higgs sector at the
high-luminosity LHC14 utilizing multi-top final states. In the framework of a
Two Higgs Doublet Model, the purely top final states () are
important channels for heavy Higgs bosons with masses in the wedge above
and at low values of , while a final state is most
relevant at moderate values of . We find, in the
channel, with , that both single and 3 lepton final
states can provide statistically significant constraints at low values of for as high as GeV. When systematics on the
background are taken into account, however, the 3 lepton final state is more
powerful, though the precise constraint depends fairly sensitively on lepton
fake rates. We also find that neither nor final states
provide constraints on additional heavy Higgs bosons with couplings to tops
smaller than the top Yukawa due to expected systematic uncertainties in the background.Comment: Added a Fig. and updated references. Matches journal version. 31
pages, 11 figure
Gauge-Higgs Unification and Radiative Electroweak Symmetry Breaking in Warped Extra Dimensions
We compute the Coleman Weinberg effective potential for the Higgs field in RS
Gauge-Higgs unification scenarios based on a bulk SO(5) x U(1)_X gauge
symmetry, with gauge and fermion fields propagating in the bulk and a custodial
symmetry protecting the generation of large corrections to the T parameter and
the coupling of the Z to the bottom quark. We demonstrate that electroweak
symmetry breaking may be realized, with proper generation of the top and bottom
quark masses for the same region of bulk mass parameters that lead to good
agreement with precision electroweak data in the presence of a light Higgs. We
compute the Higgs mass and demonstrate that for the range of parameters for
which the Higgs boson has Standard Model-like properties, the Higgs mass is
naturally in a range that varies between values close to the LEP experimental
limit and about 160 GeV. This mass range may be probed at the Tevatron and at
the LHC. We analyze the KK spectrum and briefly discuss the phenomenology of
the light resonances arising in our model.Comment: 31 pages, 9 figures. Corrected typo in boundary condition for gauge
bosons and top mass equation. To appear in PR
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