Lienard-Wiechert potentials and synchrotron radiation from a relativistic spinning particle in pseudoclassical theory

For a relativistic spinning particle with an anomalous magnetic moment, Lienard-Wiechert potentials are constructed within the pseudoclassical approach. Some specific cases of the motion of a spinning particle are considered on the basis of general expressions obtained in this study for the Lienard-Wiechert potentials. In particular, the intensity of the synchrotron radiation from a transversely polarized particle moving along a circle at a constant speed is investigated as a function of the particle spin. In the specific case of particles having no anomalous magnetic moment and moving in an external uniform magnetic field, the resulting expressions coincide with familiar formulas from the quantum theory of radiation. The spin dependence of the polarization of synchrotron radiation is investigated.     

Synchrotron radiation and the intrinsic magnetic moment of the electron

Little-studied aspects of the role of the intrinsic magnetic moment including its anomalous part in the synchrotron radiation of ultrarelativistic electrons are examined. The Fourier, transform of the polarization components of the radiation field intensity vector is written in explicit form. The spectral-angular distribution of the radiation power is found, and the terms related to the radiation of the charge and the intrinsic magnetic moment, and to quantum yield effects are determined.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 5, pp. 49–52, May, 1990.     

Diffusion of stable electron-hole plasmas in magnetic fields

The transport of a semiconductor plasma, composed of electrons and holes, can be described with the aid of moments relativ to the conditional one particle density function. To calculate these moments, an operator equation is given which was derived with the generalized Stratonovich method. This equation is extended by taking recombination and scattering with a lattice into account. The coefficient functions are determined for stable and homogeneous systems in a self-consistent manner. In particular, the spatial diffusion of test particles in a strong magnetic field is considered, neglecting quantum effects. The anomalous contribution to the diffusion across the magnetic field is calculated explicitly and compared with that for a high temperature plasma. It is shown, that anomalous diffusion is possible also in stable systems, provided the time dependence of the stochastic electric field is determined by the polarization due to the test particle.     

Gravitational divergences of the electromagnetic interactions of massive vector particles

In a search for the explanation of the finite quantum gravity corrections to anomalous moments we examined a spontaneous broken O(3) model with Yang-Mills particles and Higgs scalars coupled to gravitons. We found several new cancellations which prove that the coupling of all these particles together does not produce new counterterms apart from these which are known to exist in the subsystems and the cosmological term. The finiteness of the anomalous magnetic moment of a massive spin-1 particle is necessary for this to be valid. The finiteness of the anomalous quadrupole moment is a consequence of a known cancellation in the Einstein-Yang-Mills system. We also checked infrared finiteness and showed how to treat logarithmically divergent massless integrals in dimensional regularization.     

Contributions of weak and strong interactions to the anomalous magnetic moment of the electron

Based on Weinberg - Salam weak interaction theory, we have determined the addition to the anomalous magnetic moment of the electron arising from interaction between the electron and quantum fluctuations of the vector field (the carrier of the weak interaction). We also estimate the contribution of the strong interaction to the anomalous magnetic moment of the electron due to polarization of the quark — gluon vacuum. The overall contribution of the weak and strong interactions to the anomalous magnetic moment proves to be equal to 1·10^–12, and the contribution of the weak interaction is 2.2 times greater than the contribution of the strong interaction.Kamskii Polytechnical Institute. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 13–19, November, 1993.     

Energy Losses of a Charged Particle due to Excitation of Helicons in Plasma-Like Media

We study the energy lost by a particle moving along the helical line in a static magnetic field due to Vavilov–Cherenkov radiation of volume and surface helicons. It is found that the energy losses related to excitation of volume helicons are equivalent to the energy losses of a magnetic moment created due to the charge rotation. The magnetic moment moves at a constant velocity along the magnetic field. It is shown that collisionless damping of volume helicons in plasmas is based on the Cherenkov radiation of magnetic moment. Radiation of surface helicons by a particle does not correspond to the energy losses of a moving magnetic moment. This is related to the fact that not only magnetic (H) waves but also electric (E) waves contribute to the excitation of surface helicons, which leads to an increase in the energy losses of a particle.     

Exact quantum mechanical description of the motion of spin-1/2 particles and of spin motion in a uniform magnetic field

The Dirac-Pauli equation is used to obtain the exact equation of spin motion for spin-1/2 particles with an anomalous magnetic moment in a constant and uniform magnetic field. Exact formulas are established for the angular velocity of the revolution of such particles along circular orbits and the rotation of the particle spin with respect to momentum. Finally, a quantum mechanical equation for the motion of the particles in a strong magnetic field is derived. Zh. éksp. Teor. Fiz. 114, 448–457 (August 1998)     

Contributions to the muon’s anomalous magnetic moment from a hidden sector

The measurement of the anomalous magnetic moment of the muon provides a stringent test of the standard model and of any physics that lies beyond it. There is currently a deviation of 3.1σ between the standard model prediction for the muon’s anomalous magnetic moment and its experimental value. We calculate the contribution to the anomalous magnetic moment in theories where the muon couples to a particle in a hidden sector (that is, uncharged under the standard model) and a connector (which has nontrivial standard model gauge and hidden sector quantum numbers).     

Particle Creation in the Effective Action Method

The effect of particle creation by nonstationary external fields is considered as a radiation effect in the expectation-value spacetime. The energy of created massless particles is calculated as the vacuum contribution in the energy-momentum tensor of the expectation value of the metric. The calculation is carried out for an arbitrary quantum field coupled to all external fields entering the general second-order equation. The result is obtained as a functional of the external fields. The paper gives a systematic derivation of this result on the basis of the nonlocal effective action. Although the derivation is quite involved and touches on many aspects of the theory, the result itself is remarkably simple. It brings the quantum problem of particle creation to the level of complexity of the classical radiation problem. For external fields like the electromagnetic or gravitational field there appears a quantity, the radiation moment, that governs both the classical radiation of waves and the quantum particle production. The vacuum radiation of an electrically charged source is considered as an example. The research is aimed at the problem of backreaction of the vacuum radiation.     

Hawking Radiation of Charged Particles in Reissner-Nordström Black Hole

We extend the method that Banerjee and Majhi have used to discussHawking radiation. Under the condition that the total energy and electrical charge of spacetime are conserved, we investigate Hawking radiation of the charged black hole by a new Tortoise coordinate transformation. Taking the reaction of the radiation of the particle to the spacetime into consideration, we not only derive the radiation spectrum that satisfies the unitary principle in quantum mechanics but also show that the contribution of ingoing particlesis equal to the one of outgoing particles on the similar chemical potential term in radiation spectrum caused by charged particles.     

A different theory of anomalous magnetic moment

The invariance of Dirac's equation under rotation has been used to obtain the wave equation for a particle interacting with an electromagnetic field. The origin of the anomalous magnetic moment of a particle has been attributed to the existence of mass due to spin. These masses for a few representative particles have been calculated. In particular these calculations give a mass of 592.074 eV for a neutrino. An operator for the spin angular velocity has been constructed and the values of spin angular velocities for the particles have also been calculated.     

Interference of the transient radiation fields produced by an electric charge and a magnetic moment

The conditions for the occurrence of interference of the transient radiation fields produced by an electric charge and a magnetic moment are analyzed. The contribution of the transient radiation of a charge – magnetic moment system, depending on the orientation of the magnetic moment, to the total output has been calculated for the case of a particle escaping from a titanium target in vacuum for a photon energy of 454 eV. The possibility of harnessing the effect under consideration in developing a new type of polarimeter has been evaluated.     

On quantum corrections to Chern-Simons spinor electrodynamics

We make a detailed investigation on the quantum corrections to Chern-Simons spinor electrodynamics. Starting from Chern-Simons spinor quantum electrodynamics with the Maxwell term and by calculating the vacuum polarization tensor, electron self-energy and on-shell vertex, we explicitly show that the Ward identity is satisfied and hence verify that the physical quantities are independent of the procedure of taking at tree and one-loop levels. In particular, we find the three-dimensional analogue of the Schwinger anomalous magnetic moment term of the electron produced from the quantum corrections. Received: 9 December 1997 / Published online: 10 March 1998     

Cherenkov radiation of a spinning particle

We consider the Cherenkov radiation of a neutral particle with magnetic moment, and the spin-dependent contribution to the Cherenkov radiation of a charged spinning particle. The corresponding radiation intensity is obtained for an arbitrary value of spin and for an arbitrary spin orientation with respect to velocity. The article is published in the original.     

The Faraday law of induction for an arbitrarily moving charge

The Faraday law of electromagnetic induction for an arbitrarily moving charge is generalized and the expression for the force acting on the charge in an alternating magnetic field is obtained. It is shown that besides the Lorentz force perpendicular to the velocity of the particle, the Faraday force parallel to the particle velocity and proportional to it is acting on the charge, too. The equations of motion of the charged particle and the magnetic moment are obtained in the time-varying magnetic field. The problems of induction acceleration of charged particles (betatron) and induction heating of medium (plasma, plasma betatron) are considered.     

Polarization of spin-1 particles in a uniform magnetic field

The exact solution of the Corben–Schwinger equations is obtained for spin-1 particles without an anomalous magnetic moment in a uniform magnetic field. The exact Hamiltonian in the Foldy–Wouthuysen representation is derived. The conservation of projections of the polarization operator onto four directions is proved. The approximate conservation of projections of this operator onto the horizontal axes of the cylindrical coordinate system is established. For spin-1 particles with the anomalous magnetic moment, the Hamiltonian in the Foldy–Wouthuysen representation is deduced within first order terms in the Planck constant. Dynamics of spin-1 particles with the anomalous magnetic moment and their spins in the strong uniform magnetic field are calculated.     

用视密度加权平均二阶矩模型模拟旋流两相流动

本文用视密度加权平均代替时平均,建立了视密度加权平均的统一二阶矩两相湍流模型方程组（ＭＵＳＭ）,其中用体积分数代替了数密度,用颗粒驰豫时间作为封闭两相脉动速度关联方程耗散项的时间尺度,并引入了颗粒视在的气体速度脉动的输运方程。用ＭＵＳＭ模型模拟了旋流数为０．４７的气粒两相流动。并和实验结果及时间平均的ＵＳＭ模型的模拟结果进行了对照,两种模型均能较好地预报的两相的轴向和切向速度,轴向和切向脉动速度。此外,ＭＵＳＭ模型可以减少所用方程数,节省计算量。因此视密度加权平均的统一二阶矩两相湍流模型是一种对时间平均的统一二阶矩模型的改进,今后可以进一步扩大应用。     

Radiative corrections for extended charged particles in classical electrodynamics

Radiative effects on classical nonrelativistic charged particles are discussed in complete analogy with those arising in quantum electrodynamics. The effects originate in the interaction of the particle with its own electromagnetic fields. In particular, we derive an expression for the anomalous magnetic moment which provides both an intuitively appealing explanation of its origin and a reasonable relation to experimental values.     

The spin and the anomalous magnetic moment of the electron in stochastic electrodynamics

It is proposed that the zitterbewegung induced on a harmonically bound electron by the zero-point radiation field accounts for the spin of the electron. Assuming that the measurement of a spin projection may be taken into account phenomenologically by considering the action of only the subensemble of the zero-point field with the corresponding circular polarization, the theory gives a satisfactory account of both the spin projection and the anomalous magnetic moment.     

Anomalous Hall effect in a two dimensional electron gas with magnetic impurities

Magnetic impurities play an important role in many spintronics-related materials. Motivated by this fact, we study the anomalous Hall effect in the presence of magnetic impurities, focusing on two-dimensional electron systems with Rashba spin-orbit coupling. We find a highly nonlinear dependence on the impurity polarization, including possible sign changes. At small impurity magnetizations, this is a consequence of the remarkable result that the linear term is independent of the spin-orbit coupling strength. Near saturation of the impurity spins, the anomalous Hall conductivity can be resonantly enhanced, due to interference between potential and magnetic scattering.