15,831 research outputs found
Renormalization of the Sigma-Omega model within the framework of U(1) gauge symmetry
It is shown that the Sigma-Omega model which is widely used in the study of
nuclear relativistic many-body problem can exactly be treated as an Abelian
massive gauge field theory. The quantization of this theory can perfectly be
performed by means of the general methods described in the quantum gauge field
theory. Especially, the local U(1) gauge symmetry of the theory leads to a
series of Ward-Takahashi identities satisfied by Green's functions and proper
vertices. These identities form an uniquely correct basis for the
renormalization of the theory. The renormalization is carried out in the
mass-dependent momentum space subtraction scheme and by the renormalization
group approach. With the aid of the renormalization boundary conditions, the
solutions to the renormalization group equations are given in definite
expressions without any ambiguity and renormalized S-matrix elememts are
exactly formulated in forms as given in a series of tree diagrams provided that
the physical parameters are replaced by the running ones. As an illustration of
the renormalization procedure, the one-loop renormalization is concretely
carried out and the results are given in rigorous forms which are suitable in
the whole energy region. The effect of the one-loop renormalization is examined
by the two-nucleon elastic scattering.Comment: 32 pages, 17 figure
Recommended from our members
Highly-efficient low cost anisotropic wet etching of silicon wafers for solar cells application
In this work, a novel aqueous etching solution was investigated for texturization of silicon substrates. Nearly 30% of incident light is reflected from the surface of crystalline silicon due to its high refractive index. Surface texturization is an efficient practice to reduce surface reflection by enhancing light trapping. Newly formulated etching solution was evaluated for optical reflection, surface morphology and hydrophilicity of silicon substrates. Amazingly, experimental results demonstrate lowest optical reflectance, improved surface morphology as well as enhanced periodicity of the resulting pyramids. A remarkably lowest surface reflectance of 9.94% was achieved. Meanwhile, addition of IPA in the solution plays a major part in improving hydrophilicity of the silicon substrates
Quantum computation in silicon-vacancy centers based on nonadiabatic geometric gates protected by dynamical decoupling
Due to strong zero-phonon line emission, narrow inhomogeneous broadening, and
stable optical transition frequencies, the quantum system consisting of
negatively charged silicon-vacancy (SiV) centers in diamond is highly expected
to develop universal quantum computation. We propose to implement quantum
computation for the first time using SiV centers placed in a one-dimensional
phononic waveguide, for which quantum gates are realized in a nonadiabatic
geometric way and protected by dynamical decoupling (DD). The scheme has the
feature of geometric quantum computation that is robust to control errors and
the advantage of DD that is insensitive to environmental impact. Furthermore,
the encoding of qubits in long-lifetime ground states of silicon-vacancy
centers can reduce the effect of spontaneous emission. Numerical simulations
demonstrate the practicability of the SiV center system for quantum computation
and the robustness improvement of quantum gates by DD pulses. This scheme may
provide a promising path toward high-fidelity geometric quantum computation in
solid-state systems
Quantum contextuality for a relativistic spin-1/2 particle
The quantum predictions for a single nonrelativistic spin-1/2 particle can be
reproduced by noncontextual hidden variables. Here we show that quantum
contextuality for a relativistic electron moving in a Coulomb potential
naturally emerges if relativistic effects are taken into account. The
contextuality can be identified through the violation of noncontextuality
inequalities. We also discuss quantum contextuality for the free Dirac electron
as well as the relativistic Dirac oscillator.Comment: REVTeX4, 5 page
Vertical and longitudinal electron density structures of equatorial E- and F-regions
From global soundings of ionospheric electron density made with FORMOSAT
3/COSMIC satellites for September 2006–August 2009, day-night variations in
vertical and longitudinal structures of the electron densities in equatorial
E- and F-regions for different seasons are investigated for the first time.
The results reveal that the wavenumber-3 and wavenumber-4 patterns
dominated the nighttime (22:00–04:00 LT) F-region longitudinal structures in
solstice and in equinox seasons, respectively. In daytime (08:00–18:00 LT)
F-region, the wavenumber-4 patterns governed the longitudinal structures in
the September equinox and December solstice, and wavenumber-3 in March
equinox and June solstice respectively. A comparison of the daytime
and nighttime longitudinal electron density structures indicates that they
are approximately 180° out of phase with each other. It is believed that
this out of phase relation is very likely the result of the opposite phase
relation between daytime and nighttime nonmigrating diurnal tidal winds that
modulate background E-region dynamo electric field at different places,
leading to the day-night change in the locations of the equatorial plasma
fountains that are responsible for the formation of the F-region
longitudinal structures. Further, a good consistency between the locations
of the density structures in the same seasons of the different years for
both daytime and nighttime epochs has been noticed indicating that the
source mechanism for these structures could be the same
Six-Quark Amplitudes from Fermionic MHV Vertices
The fermionic extension of the CSW approach to perturbative gauge theory
coupled with fermions is used to compute the six-quark QCD amplitudes. We find
complete agreement with the results obtained by using the usual Feynman rules.Comment: Latex file, 16 pages, 4 figure
Experimental and Numerical Studies on Tire Tread Block Friction Characteristics Based on a New Test Device
A new device was developed for tire tread block slip friction tests. Then the friction characteristics were investigated under different loads and contact roads. Based on this, a friction model for contact between tire tread block and different road surfaces was developed. A finite element slip friction model of rubber block was developed for studying the tread contact stress, stiffness under different pattern slope angles, and ditch radius. Results indicate that friction coefficient between tread and ice road increases when the temperature decreases; different tread patterns have a certain influence on the friction coefficient; its average difference was less than 10%. Different roads impact the coefficient of friction more significantly; the greater the pattern slope, the greater the radial stiffness
- …