23,907 research outputs found
Neutrino masses, leptogenesis and dark matter in hybrid seesaw
We suggest a hybrid seesaw model where relatively ``light''right-handed
neutrinos give no contribution to the neutrino mass matrix due to a special
symmetry. This allows their Yukawa couplings to the standard model particles to
be relatively strong, so that the standard model Higgs boson can decay
dominantly to a left and a right-handed neutrino, leaving another stable
right-handed neutrino as cold dark matter. In our model neutrino masses arise
via the type-II seesaw mechanism, the Higgs triplet scalars being also
responsible for the generation of the matter-antimatter asymmetry via the
leptogenesis mechanism.Comment: 4 page
Acoustic based safety emergency vehicle detection for intelligent transport systems
A system has been investigated for the detection of incoming direction of an emergency vehicle. Acoustic detection methods based on a cross microphone array have been implemented. It is shown that source detection based on time delay estimation outperforms sound intensity techniques, although both techniques perform well for the application. The relaying of information to the driver as a warning signal has been investigated through the use of ambisonic technology and a 4 speaker array which is ubiquitous in most modern vehicles. Simulations show that accurate warning information may be relayed to the driver and afford correct action
Fermionic concurrence in the extended Hubbard dimer
In this paper, we introduce and study the fermionic concurrence in a two-site
extended Hubbard model. Its behaviors both at the ground state and finite
temperatures as function of Coulomb interaction (on-site) and
(nearest-neighbor) are obtained analytically and numerically. We also
investigate the change of the concurrence under a nonuniform field, including
local potential and magnetic field, and find that the concurrence can be
modulated by these fields.Comment: 5 pages, 7 figure
Efficient electronic entanglement concentration assisted with single mobile electron
We present an efficient entanglement concentration protocol (ECP) for mobile
electrons with charge detection. This protocol is quite different from other
ECPs for one can obtain a maximally entangled pair from a pair of
less-entangled state and a single mobile electron with a certain probability.
With the help of charge detection, it can be repeated to reach a higher success
probability. It also does not need to know the coefficient of the original
less-entangled states. All these advantages may make this protocol useful in
current distributed quantum information processing.Comment: 6pages, 3figure
Trapped interacting two-component bosons
In this paper we solve one dimensional trapped SU(2) bosons with repulsive
-function interaction by means of Bethe-ansatz method. The features of
ground state and low-lying excited states are studied by numerical and analytic
methods. We show that the ground state is an isospin "ferromagnetic" state
which differs from spin-1/2 fermions system. There exist three quasi-particles
in the excitation spectra, and both holon-antiholon and holon-isospinon
excitations are gapless for large systems. The thermodynamics equilibrium of
the system at finite temperature is studied by thermodynamic Bethe ansatz. The
thermodynamic quantities, such as specific heat etc. are obtained for the case
of strong coupling limit.Comment: 15 pages, 9 figure
Relativistic description of J/\psi dissociation in hot matter
The mass spectra and binding radii of heavy quark bound states are studied on
the basis of the reduced Bethe-Salpeter equation. The critical values of
screening masses for and bound states at a finite
temperature are obtained and compared with the previous results given by
non-relativistic models.Comment: 13 latex pages, 2 figure
Grand unification in the minimal left-right symmetric extension of the standard model
The simplest minimal left-right symmetric extension of the standard model is
studied in the high energy limit, and some consequences of the grand
unification hypothesis are explored assuming that the parity breaking scale is
the only relevant energy between the electro-weak scale and the unification
point. While the model is shown to be compatible with the observed neutrino
phenomenology, the parity breaking scale and the heavy boson masses are
predicted to be above 10^7 TeV, quite far from the reach of nowadays
experiments. Below that scale only an almost sterile right handed neutrino is
allowed with a mass M \approx 100 TeV
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