7,161 research outputs found
A supersymmetric 3-3-1 model
We build the complete supersymmetric version of a 3-3-1 gauge model using the
superfield formalism. We point out that a discrete symmetry, similar to the
R-symmetry in the minimal supersymmetric standard model, is possible to be
defined in this model. Hence we have both R-conserving and R-violating
possibilities. Analysis of the mass spectrum of the neutral real scalar fields
shown that in this model the lightest scalar Higgs has a mass upper limit, and
at the tree level it is 124.5 GeV for a given illustrative set of parameters.Comment: RevTex, extended and revised version, 20 pages, one eps figur
Left-right asymmetries and exotic vector-boson discovery in lepton-lepton colliders
By considering left-right (L-R) asymmetries we study the capabilities of
lepton colliders in searching for new exotic vector bosons. Specifically we
study the effect of a doubly charged bilepton boson and an extra neutral vector
boson appearing in a 3-3-1 model on the L-R asymmetries for the processes
, and and
show that these asymmetries are very sensitive to these new contributions and
that they are in fact powerful tools for discovery this sort of vector bosons.Comment: RevTeX, 22 pages, 12 eps figure
Soft CP violation in K-meson systems
We consider a model with soft CP violation which accommodate the CP violation
in the neutral kaons even if we assume that the Cabibbo-Kobayashi-Maskawa
mixing matrix is real and the sources of CP violation are three complex vacuum
expectation values and a trilinear coupling in the scalar potential. We show
that for some reasonable values of the masses and other parameters the model
allows to explain all the observed CP violation processes in the
- system.Comment: 19 pages, RevTeX 4. Minor modification
Supersymmetric 3-3-1 model with right-handed neutrinos
We consider the supersymmetric extension of the 3-3-1 model with right-handed
neutrinos. We study the mass spectra in the scalar and pseudoscalar sectors,
and for a given set of the input parameters, we find that the lightest scalar
in the model has a mass of 130 GeV and the lightest pseudoscalar has mass of 5
GeV. However, this pseudoscalar decouples from the at high energy scales
since it is almost a singlet under .Comment: Revtex4, 16 pages, no figure
Recent results on self-dual configurations on the torus
We review the recent progress on our understanding of self-dual SU(N)
Yang-Mills configurations on the torus.Comment: Latex 3 pages, 1 figure. Contribution to the Lat99 Proceeding
Vascular burden as a substrate for higher-level gait disorders in older adults. A review of brain mapping literature
Vascular brain burden, evaluated as white matter hyperintensities (WMH), may explain in part the higher-level gait disorders found in older adults. However, the magnitude and location of WMH as a determinant of higher-level gait disorders remain unknown. The purpose of this review was to determine if the magnitude and distribution of WMH would be associated with the presence of gait disorders in older adults. Medline was searched using the following keywords: "gait", "gait disorders, neurologic", "walking", "cerebrovascular disorders", "leukoaraiosis", "leukoencephalopathies" and "aged". Additional references were reviewed from the bibliographies, and from citation searches on key articles. Observational studies, without language restriction, published between 1995-2011 and exploring simultaneously WMH on MRI and gait performance were selected. Twenty-one studies met the selection criteria. The number of participants per study ranged from 14 to 3301 (35% to 75% female). The total WMH burden was associated with gait disorders in all studies. The largest WMH fractions associated with gait disorders were found in the frontal lobe, the centrum semiovale, the posterior limb of internal capsule, the genu and the splenium of corpus callosum. Gait velocity, stride length and step width were the gait parameters most commonly affected in the presence of WMH. The brain mapping literature supports the hypothesis that a high WMH burden is associated with gait disorders in the course of aging. This could give rise to new strategies for the prevention of higher-level gait disorders and falls in the elderly based on the management of cerebrovascular disease
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