51,109 research outputs found
OPERA superluminal neutrinos and Kinematics in Finsler spacetime
The OPERA collaboration recently reported that muon neutrinos could be
superluminal. More recently, Cohen and Glashow pointed that such superluminal
neutrinos would be suppressed since they lose their energies rapidly via
bremsstrahlung. In this Letter, we propose that Finslerian nature of spacetime
could account for the superluminal phenomena of particles. The Finsler
spacetime permits the existence of superluminal behavior of particles while the
casuality still holds. A new dispersion relation is obtained in a class of
Finsler spacetime. It is shown that the superluminal speed is linearly
dependent on the energy per unit mass of the particle. We find that such a
superluminal speed formula is consistent with data of OPERA, MINOS and
Fermilab-1979 neutrino experiments as well as observations on neutrinos from
SN1987a.Comment: 10 pages, 2 figures. Viewpoints of Finslerian special relativity on
OPERA superluminal neutrino
Tuning Kinetic Magnetism of Strongly Correlated Electrons via Staggered Flux
We explore the kinetic magnetism of the infinite- repulsive Hubbard models
at low hole densities on various lattices with nearest-neighbor hopping
integrals modulated by a staggered magnetic flux . Tuning from
0 to makes the ground state (GS) change from a Nagaoka-type ferromagnetic
state to a Haerter-Shastry-type antiferromagnetic state at a critical ,
with both states being of kinetic origin. Intra-plaquette spin correlation, as
well as the GS energy, signals such a quantum criticality. This tunable kinetic
magnetism is generic, and appears in chains, ladders and two-dimensional
lattices with squares or triangles as elementary constituents.Comment: 4 pages, 5 figures, 1 tabl
Mediating exchange bias by Verwey transition in CoO/Fe3O4 thin film
We report the tunability of the exchange bias effect by the first-order
metal-insulator transition (known as the Verwey transition) of Fe3O4 in CoO (5
nm)/Fe3O4 (40 nm)/MgO (001) thin film. In the vicinity of the Verwey
transition, the exchange bias field is substantially enhanced because of a
sharp increase in magnetocrystalline anisotropy constant from high-temperature
cubic to lowtemperature monoclinic structure. Moreover, with respect to the
Fe3O4 (40 nm)/MgO (001) thin film, the coercivity field of the CoO (5 nm)/Fe3O4
(40 nm)/MgO (001) bilayer is greatly increased for all the temperature range,
which would be due to the coupling between Co spins and Fe spins across the
interface
Vacuum Energy Density and Cosmological Constant in dS Brane World
We discuss the vacuum energy density and the cosmological constant of dS
brane world with a dilaton field. It is shown that a stable AdS brane can
be constructed and gravity localization can be realized. An explicit relation
between the dS bulk cosmological constant and the brane cosmological constant
is obtained. The discrete mass spectrum of the massive scalar field in the
AdS brane is used to acquire the relationship between the brane
cosmological constant and the vacuum energy density. The vacuum energy density
in the brane gotten by this method is in agreement with astronomical
observations.Comment: 16 pages,4 figure
Lepton masses and mixing without Yukawa hierarchies
We investigate the neutrino masses and mixing patten in a version of the
model with one extra exotic charged
lepton per family as introduced by Ozer. It is shown that an extended scalar
sector, together with a discrete symmetry, is able to reproduce a
consistent lepton mass spectrum without a hierarchy in the Yukawa coupling
constants, the former as a carefull balance between one universal see-saw and
two radiative mechanisms.Comment: 7 pages, 2 figures, accepted for publication in Phys. Rev. D
Spin and Rotations in Galois Field Quantum Mechanics
We discuss the properties of Galois Field Quantum Mechanics constructed on a
vector space over the finite Galois field GF(q). In particular, we look at
2-level systems analogous to spin, and discuss how SO(3) rotations could be
embodied in such a system. We also consider two-particle `spin' correlations
and show that the Clauser-Horne-Shimony-Holt (CHSH) inequality is nonetheless
not violated in this model.Comment: 21 pages, 11 pdf figures, LaTeX. Uses iopart.cls. Revised
introduction. Additional reference
Surface response of spherical core-shell structured nanoparticle by optically induced elastic oscillations of soft shell against hard core
The optically induced oscillatory response of a spherical two-component,
shell-core structured, nanoparticle by nodeless elastic vibrations of soft
peripheral shell against hard and dynamically immobile inner core is
considered. The eigenfrequencies of the even-parity, spheroidal and odd-parity
torsional vibrational modes trapped in the finite-depth shell are obtained
which are of practical interest for modal specification of individual
resonances in spectra of resonant scattering of long wavelength electromagnetic
waves by ultrafine particles.Comment: Surface Review and Letters (World Scientific) Year: 2009 Vol: 16
Issue: 1 (February 2009) Page: 5 - 1
Multi-Atomic Mirror for Perfect Reflection of Single Photons in A Wide Band of Frequency
A resonant two level atom doped in one dimensional waveguide behaves as a
mirror, but this single-atom "mirror" can only reflect single photon perfectly
at a specific frequency. For a one dimensional coupled-resonator waveguide, we
propose to extend the perfect reflection region from a specific frequency to a
wide band by placing many atoms individually in the resonators in a finite
coordinate region of the waveguide. Such a doped resonator array promises us to
control the propagation of a practical photon wave packet with certain momentum
distribution instead of a single photon, which is ideally represented by a
plane wave with specific momentum. The studies based on the discrete-coordinate
scattering theory display that such hybrid structure indeed provides a
near-perfect reflection for single photon in a wide band. We also calculated
photon group velocity distribution, which shows that the perfect reflection
with wide band exactly corresponds to the stopping light region.Comment: 8 pages, 10 figure
- …
