8,328 research outputs found
Revisit to Non-decoupling MSSM
Dipole operator requires the helicity
flip in the involving quark states thus the breaking of chiral . On the other hand, the -quark mass generation is also a
consequence of chiral symmetry breaking. Therefore,
in many models, there might be strong correlation between the
and quark Yukawa coupling. We use non-decoupling MSSM model to illustrate
this feature. The light Higgs boson may evade the direct search experiments at
LEPII or Tevatron while the 125 GeV Higgs-like boson is identified as the heavy
Higgs boson in the spectrum. A light charged Higgs is close to the heavy Higgs
boson which is of 125 GeV and its contribution to requires
large supersymmetric correction with large PQ and symmetry breaking. The
large supersymmetric contribution at the same time significantly modifies the
quark Yukawa co upling. With combined flavor constraints
and and direct constraints on Higgs properties, we
find best fit scenarios with light stop of (500 GeV), negative
around -750 GeV and large -term of 2-3 TeV. In addition, reduction in
partial width may also result in large enhancement of
decay branching fraction. Large parameter region in the survival space under
all bounds may be further constrained by if no excess of
is confirmed at LHC. We only identify a small parameter region with
significant decay that is consistent with all bounds and reduced
decay branching fraction.Comment: 18pages, 6 figure
Electronic structures of [111]-oriented free-standing InAs and InP nanowires
We report on a theoretical study of the electronic structures of the
[111]-oriented, free-standing, zincblende InAs and InP nanowires with hexagonal
cross sections by means of an atomistic , spin-orbit interaction
included, nearest-neighbor, tight-binding method. The band structures and the
band state wave functions of these nanowires are calculated and the symmetry
properties of the bands and band states are analyzed based on the
double point group. It is shown that all bands of these nanowires are doubly
degenerate at the -point and some of these bands will split into
non-degenerate bands when the wave vector moves away from the
-point as a manifestation of spin-splitting due to spin-orbit
interaction. It is also shown that the lower conduction bands of these
nanowires all show simple parabolic dispersion relations, while the top valence
bands show complex dispersion relations and band crossings. The band state wave
functions are presented by the spatial probability distributions and it is
found that all the band states show -rotation symmetric probability
distributions. The effects of quantum confinement on the band structures of the
[111]-oriented InAs and InP nanowires are also examined and an empirical
formula for the description of quantization energies of the lowest conduction
band and the highest valence band is presented. The formula can simply be used
to estimate the enhancement of the band gaps of the nanowires at different
sizes as a result of quantum confinement.Comment: 9 pages, 8 figures. arXiv admin note: substantial text overlap with
arXiv:1502.0756
Method for arbitrary phase transformation by a slab based on transformation optics and the principle of equal optical path
The optical path lengths travelled by rays across a wavefront essentially
determine the resulting phase front irrespective of the shape of a medium
according to the principle of equal optical path. Thereupon we propose a method
for the transformation between two arbitrary wavefronts by a slab, i.e. the
profile of the spatial separation between the two wavefronts is taken to be
transformed to a plane surface. Interestingly, for the mutual conversion
between planar and curved wavefronts, the method reduce to an inverse
transformation method in which it is the reversed shape of the desired
wavefront that is converted to a planar one. As an application, three kinds of
phase transformation are realized and it is found that the transformation on
phase is able to realize some important properties such as phase reversal or
compensation, focusing, and expanding or compressing beams, which are further
confirmed by numerical simulations. The slab can be applied to realizing
compact electromagnetic devices for which the values of the refractive index or
the permittivity and permeability can be high or low, positive or negative, or
near zero, depending on the choice of coordinate transformations.Comment: 8 pages, 6 figure
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