349 research outputs found
Neutralinos in E_6 inspired supersymmetric U(1)' models
The neutralino sector in E_6 inspired supersymmetric models with extra
neutral gauge bosons and singlet Higgs fields contains additional gaugino and
singlino states compared to the MSSM. We discuss the neutralino mixing in rank
5 and rank 6 models and analyze the supersymmetric parameter space where the
light neutralinos have mainly singlino or MSSM character. The neutralino
character, resonance effects of the new gauge bosons and, assuming mSUGRA-type
RGEs, different selectron masses lead to significant differences between the
MSSM and the extended models in neutralino production at an e^+e^- linear
collider. Beam polarization may improve the signatures to distinguish between
the models. In an appendix, we present the mass terms of the gauge bosons,
charginos and sfermions which show a significant different mass spectrum than
in the MSSM and give all relevant neutralino couplings.Comment: 26 pages, LaTeX, 5 eps figures; version to be published in EPJ
Neutralino Production with Polarized Beams in Extended Supersymmetric Models
We discuss associated neutralino production e^+ e^- --> \tilde{\chi}^0_1
\tilde{\chi}^0_2 with both beams polarized in the MSSM, NMSSM and an E_6 model.
It is shown that neutralinos with a large singlino component can be produced at
a high luminosity linear collider in a broad parameter range. Polarization
effects in the extended models are compared over the whole parameter space
where the lightest neutralino is mainly a singlino. We explain the complete
different behavior of these models in some parameter regions, which may help to
identify the respective supersymmetric model.Comment: 10 pages, LaTeX, 10 eps figures, contribution to the Proceedings of
the "2nd Joint ECFA/DESY Study on Physics and Detectors for a Linear
Electron-Positron Collider
Identifying the NMSSM by the interplay of LHC and ILC
The interplay between the LHC and the International Linear Collider
(ILC) with GeV might be crucial for the discrimination between
the minimal and next-to-minimal supersymmetric standard model. We present an
NMSSM scenario, where the light neutralinos have a significant singlino
component, that cannot be distinguished from the MSSM by cross sections and
mass measurements. Mass and mixing state predictions for the heavier
neutralinos from the ILC analysis at different energy stages and comparison
with observation at the LHC, lead to clear identification of the particle
character and identify the underlying supersymmetric model.Comment: 8 pages, 2 eps figures, revtex4 style Contribution to the `2005
International Linear Collider Workshop - Stanford, U.S.A.
CP asymmetries in chargino production and decay: the three-body decay case
We study CP violation in chargino production and decay in the Minimal
Supersymmetric Standard Model (MSSM) with complex parameters at an e^+ e^-
linear collider with longitudinally polarized beams. We investigate
CP-sensitive asymmetries by means of triple product correlations and study
their dependence on the complex parameters M_1 and mu. We give numerical
predictions for the asymmetries and their measurability at the future
International Linear Collider. Our results show that the CP asymmetries can be
measured in a large region of the MSSM parameter space.Comment: 22 pages, LaTeX, 8 figures; v2: structural changes and references
added, main conclusions unchanged, published versio
Impact of CP phases on SUSY particle production and decays
We report on the results of a phenomenological study of top squarks
(stop_{1,2}) and bottom squarks (sbottom_{1,2}) in the Minimal Supersymmetric
Standard Model (MSSM) with complex parameters A_t, A_b, mu and M_1. In
particular we focus on the CP phase dependence of the branching ratios of
stop_{1,2} and sbottom_{1,2} decays. We find that the effect of the phases on
the stop_{1,2} and sbottom_{1,2} decays can be quite significant in a large
region of the MSSM parameter space. We also study a CP asymmetry in sfermion
decays.Comment: 10 pages, 8 eps figures, LaTeX, uses JHEP3.cls; talk given at the
International Workshop on Astroparticle and High Energy Physics (AHEP),
Valencia, Spain, 14-18 Oct. 200
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