Characteristics of synchrotron radiation of longitudinally polarized spinning particle in the pseudoclassical theory

Spin dependencies of the intensity and polarization of the synchrotron radiation of the longitudinally polarized particle performing uniform circular motion in the magnetic field are investigated.Comment: LATEX, 6 pages, misprints correcte

Pseudoclassical neutrino in the external electromagnetic field

The problem of the passage of the neutral massless particle with anomalous magnetic moment through the external electromagnetic field is considered both in pseudoclassical and quantum mechanics. The quantum description uses the hamiltonian in the Foldy--Wouthuysen representation, obtained from the pseudoclassical hamiltonian of the massive charged particle with anomalous magnetic moment in interaction with the external electromagnetic field using Weyl quantization scheme.Comment: LATEX, 10 pages, no figure

Pseudoclassical and quantum theory of the D=2n dimensional relativistic spinning particle with anomalous "magnetic" moment in the external Yang-Mills field

The pseudoclassical hamiltonian and action of the $D=2n$ dimensional Dirac particle with anomalous magnetic moment interacting with the external Yang-Mills field are found. The Bargmann-Michel-Telegdi equation of motion for the Pauli-Lubanski vector is deduced. The canonical quantization of $D=2n$ dimensional Dirac spinning particle with anomalous magnetic moment in the external Yang-Mills field is carried out in the gauge which allows to describe simultaneously particles and antiparticles (massive and massless) already at the classical level. Pseudoclassical Foldy-Wouthuysen transformation is used to obtain canonical (Newton-Wigner) coordinates and in terms of these variables the theory is quantized.Comment: 10 pages, latex fil

Pseudoclassical theory of Mayorana--Weyl particle

A pseudoclassical theory of Weyl particle in the space--time dimensions $D=2n$ is constructed. The canonical quantization of that pseudoclassical theory is carried out and it results in the theory of the $D=2n$ dimensional Weyl particle in the Foldy--Wouthuysen representation. A quantum mechanics of the neutral Weyl particle in even--dimensional space--time is suggested and the connection of this theory with the theory of Mayorana--Weyl particle in QFT is discussed for D=10.Comment: LATEX, 14 pages, no figures, replacement because of e-mail transfer fault

About dual two-dimensional oscillator and Coulomb-like theories on a plane

We present a mathematically rigorous quantum-mechanical treatment of a two-dimensional nonrelativistic quantum dual theories (with oscillator and Coulomb like potentials) on a plane and compare their spectra and the sets of eigenfunctions. All self-adjoint Schrodinger operators for these theories are constructed and rigorous solutions of the corresponding spectral problems are presented. The first part of the problem is solved by using a method of specifying s.a. extensions by (asymptotic) s.a. boundary conditions. Solving spectral problems, we follow the Krein's method of guiding functionals. We show, that there is one to one correspondence between the spectral points of dual theories in the planes energy-coupling constants not only for discrete, but also for continuous spectra.Comment: 44 page

Lienard-Wiechert potential and synchrotron radiation of a relativistic spinning particle in the pseudoclassical theory

Lienard-Wiechert potentials of the relativistic spinning particle with anomalous magnetic moment in pseudoclassical theory are constructed. General expressions for the Lienard-Wiechert potentials are used for investigation of some specific cases of the motion of the spinning particle. In particular the spin dependence of the intensity of the synchrotron radiation of the transversely polarized particle performing uniform circular motion is considered. When the movement of the particle in external homogeneous magnetic field the obtained formulae coincide with those known from quantum theory of radiation. The dependence of the polarization of the synchrotron radiation on the spin of the particle is investigated.Comment: Latex, 15 pages, misprints corrected, reference adde

Structure and energetics of Ni clusters with up to 150 atoms

We present a method (the Aufbau/Abbau method) for optimizing the structure of a whole series of clusters without making any assumptions on the structure. Subsequently, the method is combined with the embedded-atom method in determining the structure of the two energetically lowest isomers of Ni_N clusters with N up to 150. Finally, various analytical descriptors are introduced that are used in studying the overall shape of the clusters, their structure and stability, and possible growth and dissociation processes.Comment: 16 pages, 5 figure

Theoretical study of structure and energetics of gold clusters with the EAM method

Using the Embedded Atom Method as developed by Voter and Chen in combination with the {\it variable metric/quasi-Newton} and our own {\it Aufbau/Abbau} methods, we have identified the three most stable isomers of Au$_N$ clusters with $N$ up to 150. For the first time clusters with tetrahedral symmetry are found to form the ground states of Au$_{17}$ and Au$_{34}$. The Au$_{54}$ {\it icosahedron} without a central atom and the Au$_{146}$ {\it decahedron} are found to be particularly stable, whereas the highly symmetric second and third Mackay icosahedra that could have been obtained for $N$ = 55 and 147, respectively, do not correspond to the particularly stable structures. The three lowest-lying isomers of Au$_{55}$ and Au$_{147}$ are low-symmetrical structures. Various structural and energetic properties are analysed, such as stability function, occurrence of magic-sized clusters, construction of icosahedral and {\it fcc} shells, and cluster growth.Comment: To appear in Z. Phys. Che

AA-dependence of coherent electroproduction of ρ0\rho^{0} mesons on nuclei in forward direction

This article presents the $A$-dependence of the differential cross section for the coherent electroproduction of vector mesons on nuclei in forward direction, at fixed values of longitudinal momentum transfer $q_{L}$. It is shown that such cross section has complicated behavior over the atomic mass number $A$ with local minimums and maximums. It is also shown that a ratio of the real to the imaginary parts of the forward coherent amplitude on nuclei $\alpha_{A} = \Re e{f_{A}} / \Im m{f_{A}}$ has breaking points at some values of $A$. Comparison of the behaviors of the normalized cross section $\Big(\frac{d\sigma}{d\Omega}\Big)_{A}\Big/\Big(\frac{d\sigma}{d\Omega}\Big)_{N}$ and $\alpha_{A}$ over $A$ shows that the location of minimums of the cross section are very close to the breaking points of $\alpha_{A}$

Adiabatic Transparency of Multilevel Atomic Media for Short High-intensity Pulses

We consider a medium of multilevel atomic systems interacting with radiation pulses. A relatively simple technique of analytic calculations is proposed, which allows revealing all necessary conditions (with sufficient conditions to be checked separately) imposed on the interaction parameters, for which the mean dipole moment of a multilevel atomic medium vanishes, i.e., the medium becomes transparent via adiabatic interaction. The proposed technique is based on the method of quasienergies and illustrated for three- and five-level atomic systems. The necessary conditions for the propagation length where the interaction adiabaticity is preserved in the medium are obtained