2,392 research outputs found
NMSSM From Alternative Deflection in Generalized Deflected Anomaly Mediated SUSY Breaking
We propose a new approach to generate messenger-matter interactions in
deflected anomaly mediated SUSY breaking mechanism from typical holomorphic
messenger-matter mixing terms in the Kahler potential. This approach is a
unique feature of AMSB and has no analog in GMSB-type scenarios. New coupling
strengths from the scaling of the (already known) Yukawa couplings always
appear in this approach. With messenger-matter interactions in deflected AMSB,
we can generate a realistic soft SUSY breaking spectrum for next-to-minimal
supersymmetric standard model(NMSSM). Successful electroweak symmetry breaking
conditions, which is not easy to satisfy in NMSSM for ordinary AMSB-type
scenario, can be satisfied in a large portion of parameter space in our
scenarios. We study the relevant phenomenology for scenarios with (Bino-like)
neutralino and axino LSP, respectively. In the case of axino LSP, the SUSY
contributions to can possibly account for the muon
discrepancy. The corresponding gluino masses, which are found to below 2.2 TeV,
could be tested soon at LHC.Comment: 25pages, 2 figure
Collider and Dark Matter Phenomenology of Models with Mirage Unification
We examine supersymmetric models with mixed modulus-anomaly mediated SUSY
breaking (MM-AMSB) soft terms which get comparable contributions to SUSY
breaking from moduli-mediation and anomaly-mediation. The apparent (mirage)
unification of soft SUSY breaking terms at Q=mu_mir not associated with any
physical threshold is the hallmark of this scenario. The MM-AMSB structure of
soft terms arises in models of string compactification with fluxes, where the
addition of an anti-brane leads to an uplifting potential and a de Sitter
universe, as first constructed by Kachru {\it et al.}. The phenomenology mainly
depends on the relative strength of moduli- and anomaly-mediated SUSY breaking
contributions, and on the Higgs and matter field modular weights, which are
determined by the location of these fields in the extra dimensions. We
delineate the allowed parameter space for a low and high value of tan(beta),
for a wide range of modular weight choices. We calculate the neutralino relic
density and display the WMAP-allowed regions. We show the reach of the CERN LHC
and of the International Linear Collider. We discuss aspects of MM-AMSB models
for Tevatron, LHC and ILC searches, muon g-2 and b->s \gamma branching
fraction. We also calculate direct and indirect dark matter detection rates,
and show that almost all WMAP-allowed models should be accessible to a
ton-scale noble gas detector. Finally, we comment on the potential of colliders
to measure the mirage unification scale and modular weights in the difficult
case where mu_mir>>M_GUT.Comment: 34 pages plus 42 EPS figures; version with high resolution figures is
at http://www.hep.fsu.edu/~bae
Higgs mass, muon g-2, and LHC prospects in gauge mediation models with vector-like matters
Recently the ATLAS and CMS collaborations presented preliminary results of
Standard Model Higgs searches and reported excesses of events for a Higgs boson
at 124-126 GeV. Such a Higgs mass can be naturally realized, simultaneously
explaining the muon g-2 anomaly, in gauge-mediated SUSY breaking models with
extra vector-like matters. Upper bounds are obtained on the gluino mass,
m_{\tilde g}\lesssim 1.2 (1.8) TeV, and on the extra vector-like quark mass,
M_{Q'} \lesssim 1.0 (1.8) GeV, in the parameter region where the Higgs boson
mass is 124-126 GeV and the muon g-2 is consistent with the experimental value
at the 1 sigma (2 sigma) level. The LHC prospects are explored in the parameter
region. It is found that some of the regions are already excluded by the LHC,
and most of the parameter space is expected to be covered at \sqrt{s} = 14 TeV.
A study on the extra vector-like quarks, especially current bounds on their
masses and prospects for future searches, is also included.Comment: 28 pages, 10 figure
Supernatural Supersymmetry: Phenomenological Implications of Anomaly-Mediated Supersymmetry Breaking
We discuss the phenomenology of supersymmetric models in which supersymmetry
breaking terms are induced by the super-Weyl anomaly. Such a scenario is
envisioned to arise when supersymmetry breaking takes place in another world,
i.e., on another brane. We review the anomaly-mediated framework and study in
detail the minimal anomaly-mediated model parametrized by only 3+1 parameters:
M_aux, m_0, \tan\beta, and sign(\mu). The renormalization group equations
exhibit a novel "focus point" (as opposed to fixed point) behavior, which
allows squark and slepton masses to be far above their usual naturalness
bounds. We present the superparticle spectrum and highlight several
implications for high energy colliders. Three lightest supersymmetric particle
(LSP) candidates exist: the Wino, the stau, and the tau sneutrino. For the Wino
LSP scenario, light Wino triplets with the smallest possible mass splittings
are preferred; such Winos are within reach of Run II Tevatron searches.
Finally, we study a variety of sensitive low energy probes, including b -> s
gamma, the anomalous magnetic moment of the muon, and the electric dipole
moments of the electron and neutron.Comment: 32 pages, 17 figure
Recent Muon g-2 Result in Deflected Anomaly-Mediated Supersymmetry Breaking
We study the deflected anomaly-mediated supersymmetry breaking (AMSB)
scenario in the light of the recent result of the muon g-2 from Brookhaven E821
experiment. The E821 result suggests the deviation from the SM prediction,
though there remain unsettled uncertainties. We find that the supersymmetric
contribution to the muon g-2 can be \mathcal{O}(10^{-9}), large enough to fill
the deviation, with other experimental constraints satisfied. In particular,
the Higgs mass and b \to s \gamma put severe constraints on the model and large
\tan\beta is favored to enhance the muon g-2.Comment: 13 pages, 6 figure
SUSY Phenomenology of KKLT Flux Compactifications
We study SUSY phenomenology of the KKLT (Kachru-Kallosh-Linde-Trivedi)
scenario of string theory compactifications with fluxes. This setup leads to a
specific pattern of soft masses and distinct phenomenological properties. In
particular, it avoids the cosmological gravitino/moduli problems. Remarkably,
the model allows for the correct abundance of SUSY dark matter consistently
with all experimental constraints including the bound on the Higgs mass, b-->s
gamma, etc. This occurs for both small and large tan beta, and requires the
SUSY spectrum above 1 TeV.Comment: 23 pages, 8 figures; v2: erratum attache
Natural Split Mechanism for Sfermions: =2 Supersymmetry in Phenomenology
We suggest a natural split mechanism for sfermions based on =2
supersymmetry (SUSY). =2 SUSY protects a sfermion in an =2 multiplet from
gaining weight by SUSY breaking. Therefore, if partly =2 SUSY is effectively
obtained, a split spectrum can be realized naturally. As an example of the
natural split mechanism, we build a gauge-mediated SUSY breaking-like model
assuming =2 SUSY is partly broken in a UV theory. The model explains the
Higgs boson mass and the muon anomalous magnetic dipole moment within
level with a splitting sfermion spectrum. The model has seven light
sparticles described by three free parameters and predicts a new chiral
multiplet, sb: the =2 partner of the vector multiplet. The
bini, the fermion component of the sb, weighs MeVs. We mention the experimental
and the cosmological aspects of the model.Comment: 17 pages and 3 figures, Version accepted for publication in PL
- âŠ