818 research outputs found
Long-lived Charginos in the Focus-point Region of the MSSM Parameter Space
We analyse the possibility to get light long-lived charginos within the
framework of the MSSM with gravity mediated SUSY breaking. We find out that
this possibility can be realized in the so-called focus-point region of
parameter space. The mass degeneracy of higgsino-like chargino and two
higgsino-like neutralinos is the necessary condition for a long lifetime. It
requires the fine-tuning of parameters, but being a single additional
constraint in the whole parameter space it can be fulfilled in the Constrained
MSSM along the border line where radiative electroweak symmetry breaking fails.
In a narrow band close to the border line the charginos are long-lived
particles. The cross-sections of their production and co-production at the LHC
via electroweak interaction reach a few tenth of pb.Comment: LaTeX, 11 pages, 11 eps figure
Production of Long-Lived Sleptons at LHC
We analyse the MSSM parameter space and discuss the narrow band near the
so-called co-annihilation region where sleptons may be long-lived particles.
This region is consistent with the WMAP restrictions on the Dark matter and
depends on the value of . In this region staus are long-lived and
may go through the detector. Due to a relatively small mass (150 850
GeV) their production cross-section at LHC may reach a few % pb.Comment: LaTex, 8 pages, 6 eps figure
A gobal fit to the anomalous magnetic moment, Higgs limit and b->s gamma in the constrained MSSM
New data on the anomalous magnetic moment of the muon together with the b->s
gamma decay rate and Higgs limits are considered within the supergravity
inspired constrained minimal supersymmetric model. We perform a global
statistical chi2 analysis of these data and show that the allowed region of
parameter space is bounded from below by the Higgs limit, which depends on the
trilinear coupling and from above by the anomalous magnetic moment.Comment: 3 pages, To appear in Proc. of SUSY01, Dubna (Russia
Second-harmonic vortex generation with a poled glass
A Simple method for nonlinear vortex generation is presented. Spin-to-Orbital transfer with total angular momentum conservation between photons at the fundamental and at the second-harmonic frequency is demonstrated
The b->sgamma rate and Higgs boson limits in the Constrained Minimal Supersymmetric Model
New NLO b->sgamma calculations have become available using resummed radiative
corrections. Using these calculations we perform a global fit of the
supergravity inspired constrained minimal supersymmetric model (CMSSM). We find
that the resummed calculations show similar constraints as the LO calculations,
namely that only with a relatively heavy supersymmetric mass spectrum of the
order of 1 TeV the b-\tau Yukawa unification and the b->sgamma rate can coexist
in the large tanb scenario. The resummed b->sgamma calculations are found to
reduce the renormalization scale uncertainty considerably. The low tanb
scenario is excluded by the present Higgs limits from LEP II. The constraint
from the Higgs limit in the plane is severe, if the trilinear
coupling A_0 at the GUT scale is fixed to zero, but is considerably reduced for
. The relatively heavy SUSY spectrum required by \besg
corresponds to a Higgs mass of m_h=119\pm 1~ (stop masses)}\pm
2~(theory)~\pm~3 (top mass) GeV in the CMSSM.Comment: latex + 7 eps figs, 14 pages, final version to be published in EPJ
Advances and prospects of frequency doublers based on periodically poled silica fibres
Record high efficient frequency doublers in periodically poled silica fibres are demonstrated for light generation at 532 nm and 775 nm. The onset of nonlinear conductivity is shown to limit the maximum χ(2) in glass
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