6,932 research outputs found
The Higgs masses and explicit CP violation in the gluino-axion model
In this work, we adress the phenomenological consequences of explicit CP
violation on direct Higgs-boson searches at high energy colliders. Having a
restricted parameter space, we concentrate on the recently proposed
gluino-axion model, and investigate the CP violation capability of the model
subject to the recent experimental data. It is shown that the Higgs masses as
well as their CP compositions are quite sensitive to the supersymmetric CP
phases. The lightest Higgs is found to be nearly CP even to a good
approximation whilst the remaining two heavy scalars do not have definite CP
parities.Comment: 20 pp, 14 eps figs, title is changed, the manuscript is improved
using the latest experimental data, some figures and references adde
Effects of Curvature-Higgs Coupling on Electroweak Fine-Tuning
It is shown that, nonminimal coupling between the Standard Model (SM) Higgs
field and spacetime curvature, present already at the renormalizable level, can
be fine-tuned to stabilize the electroweak scale against power-law ultraviolet
divergences. The nonminimal coupling acts as an extrinsic stabilizer with no
effect on the loop structure of the SM, if gravity is classical. This novel
fine-tuning scheme, which could also be interpreted within Sakharov's induced
gravity approach, works neatly in extensions of the SM involving additional
Higgs fields or singlet scalars.Comment: 11 pp. Added reference
Realistic Gluino Axion Model Consistent with Supersymmetry Breaking at the TeV Scale
The recently proposed model of using the dynamical phase of the gluino to
solve the strong CP problem is shown to admit a specific realization in terms
of fundamental singlet superfields, such that the breaking of supersymmetry
occurs only at the TeV scale, despite the large axion scale of 10^{9} to
10^{12} GeV. Phenomenological implications are discussed.Comment: 12 pp, 2 fig
CP violation as a probe of flavor origin in Supersymmetry
We address the question of the relation between supersymmetry breaking and
the origin of flavor in the context of CP violating phenomena. We prove that,
in the absence of the Cabibbo-Kobayashi-Maskawa phase, a general Minimal
Supersymmetric Standard Model with all possible phases in the soft-breaking
terms, but no new flavor structure beyond the usual Yukawa matrices, can never
give a sizeable contribution to , or
hadronic CP asymmetries. Observation of supersymmetric contributions to
CP asymmetries in B decays would hint at a non-flavor blind mechanism of
supersymmetry breaking.Comment: Reference added. 7 pages, no figure
Shear-Viscosity to Entropy Density Ratio of a Relativistic Hadron Gas
Ultrarelativistic heavy-ion collisions at the Relativistic Heavy-Ion Collider
(RHIC) are thought to have produced a state of matter called the
Quark-Gluon-Plasma, characterized by a very small shear viscosity to entropy
density ratio , near the lower bound predicted for that quantity by
Anti-deSitter space/Conformal Field Theory (AdS/CFT) methods. As the produced
matter expands and cools, it evolves through a phase described by a hadron gas
with rapidly increasing . We calculate as a function of
temperature in this phase and find that its value poses a challenge for viscous
relativistic hydrodynamics, which requires small values of throughout
the entire evolution of the reaction in order to successfully describe the
collective flow observables at RHIC. We show that the inclusion of non-unit
fugacities will reduce in the hadronic phase, yet not sufficiently to
be compatible with viscous hydrodynamics. We therefore conclude that the origin
of the low viscosity matter at RHIC must be in the partonic phase of the
reaction.Comment: 4 pages, 4 figures: Modified figures and revised discussion of
entropy calculatio
On the Sources of CP-violation Contributing to the Electric Dipole Moments
In the framework of seesaw mechanism embedded in the constrained Minimal
Supersymmetric Standard Model (cMSSM), phases of neutrino Yukawa coupling,
-term and -terms can all contribute to the Electric Dipole Moment (EDM)
of the electron. We discuss and classify the situations for which by combined
analysis of the upcoming results on , and
discriminating between these sources will be possible.Comment: 6 pages, 4 figures, talk presented at IPM-LHP06, Tehran, Ira
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