1,779 research outputs found
On Influence of Intensive Stationary Electromagnetic Field on the Behavior of Fermionic Systems
Exact solutions of Schroedinger and Pauli equations for charged particles in
an external stationary electromagnetic field of an arbitrary configuration are
constructed. Green functions of scalar and spinor particles are calculated in
this field. The corresponding equations for complex energy of particles bounded
by short range potential are deduced. Boundary condition typical for delta -
potential is not used in the treatment. Explicit analytical expressions are
given for the shift and width of a quasistationary level for different
configurations of the external field. The critical value of electric field in
which the idea of quasistationary level becomes meaningless is calculated. It
is shown that the common view on the stabilizing role of magnetic field
concerns only scalar particles.Comment: 15 pages, no figures, LaTeX2
Towards a Maximal Mass Model
We investigate the possibility to construct a generalization of the Standard
Model, which we call the Maximal Mass Model because it contains a limiting mass
for its fundamental constituents. The parameter is considered as a new
universal physical constant of Nature and therefore is called the fundamental
mass. It is introduced in a purely geometrical way, like the velocity of light
as a maximal velocity in the special relativity. If one chooses the Euclidean
formulation of quantum field theory, the adequate realization of the limiting
mass hypothesis is reduced to the choice of the de Sitter geometry as the
geometry of the 4-momentum space. All fields, defined in de Sitter p-space in
configurational space obey five dimensional Klein-Gordon type equation with
fundamental mass as a mass parameter. The role of dynamical field variables
is played by the Cauchy initial conditions given at , guarantying the
locality and gauge invariance principles. The corresponding to the geometrical
requirements formulation of the theory of scalar, vector and spinor fields is
considered in some detail. On a simple example it is demonstrated that the
spontaneously symmetry breaking mechanism leads to renormalization of the
fundamental mass . A new geometrical concept of the chirality of the fermion
fields is introduced. It would be responsible for new measurable effects at
high energies . Interaction terms of a new type, due to the existence
of the Higgs boson are revealed. The most intriguing prediction of the new
approach is the possible existence of exotic fermions with no analogues in the
SM, which may be candidate for dark matter constituents.Comment: 28 page
Study the spin configuration and the saturation magnetization of manganese-zinc ferrite nanoparticles by the Monte Carlo method
In this work, the simulations of magnetic properties of nano-sized manganese ferrite particles with zinc replacement were performed. The percentage of replacement laid in range from 0% to 80%. The parameters of particles, including exchange integrals, were taken from experimental data received for MnxZn1-xFe2O4. The sizes of particles and thickness of defective surface layer were taken, taking into account real sizes distribution for manganese nanoparticles received by the way of mechanochemical synthesis. Simulations were performed using the Monte-Carlo methods, Metropolis algorithm
Scalar and Spinor Particles with Low Binding Energy in the Strong Stationary Magnetic Field Studied by Means of Two-and Three-Dimensional Models
On the basis of analytic solutions of Schrodinger and Pauli equations for a
uniform magnetic field and a single attractive -potential the
equations for the bound one-active electron states are discussed. It is vary
important that ground electron states in the magnetic field essentially
different from the analog state of spin-0 particles that binding energy has
been intensively studied at more then forty years ago. We show that binding
energy equations for spin-1/2 particles can be obtained without using of a
well-known language of boundary conditions in the model of -potential
that has been developed in pioneering works. Obtained equations are used for
the analytically calculation of the energy level displacements, which
demonstrate nonlinear dependencies on field intensities. It is shown that in a
case of the weak intensity a magnetic field indeed plays a stabilizing role in
considering systems. However the strong magnetic field shows the opposite
action. We are expected that these properties can be of importance for real
quantum mechanical fermionic systems in two- and three-dimensional cases.Comment: 18 page
Superhyperfine interactions in Ce3+ doped LiYF4 crystal: ENDOR measurements
The first observation of the resolved Mims electron-nuclear double resonance
(ENDOR) spectra from the nearby and remote nuclei of 19F and 7Li nuclei on
impurity Ce3+ ions in LiYF4 crystal is reported. It shows that LiYF4:Ce3+
system can be exploited as a convenient matrix for performing spin
manipulations and adjusting quantum computation protocols while ENDOR technique
could be used for the investigation of electron-nuclear interaction with all
the nuclei of the system and exploited for the electron-nuclear spin
manipulations.Comment: 4 pages, 2 figures, 1 Table. Reported on Theor-2017 (Kazan, Russia)
Conferenc
Effects of Vacuum Polarization in Strong Magnetic Fields with an Allowance Made for the Anomalous Magnetic Moments of Particles
Given the anomalous magnetic moments of electrons and positrons in the
one-loop approximation, we calculate the exact Lagrangian of an intense
constant magnetic field that replaces the Heisenberg-Euler Lagrangian in
traditional quantum electrodynamics (QED). We have established that the derived
generalization of the Lagrangian is real for arbitrary magnetic fields. In a
weak field, the calculated Lagrangian matches the standard Heisenberg-Euler
formula. In extremely strong fields, the field dependence of the Lagrangian
completely disappears, and the Lagrangian tends to a constant determined by the
anomalous magnetic moments of the particles.Comment: 19 pages, 3 figure
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