Model Of Relativistic Particle Research Articles

Relativistic theory of free anyons reexamined.

We reconsider some recent models of free relativistic particles with arbitrary spin (anyons) in 2+1 dimensions. It is shown that even if the mass shell and the symplectic two-form conditions (essential for describing anyons) are satisfied, there are other consistency requirements which determine the validity (or otherwise) of a specific model. The implications of this analysis for electromagnetic coupling are also discussed. {copyright} {ital 1996 The American Physical Society.}

Dynamics of relativistic particles with Lagrangians dependent on acceleration

Models of relativistic particles with Lagrangians ℒ(k1), depending on the curvature of the worldline k1, are considered. By making use of the Frenet basis, the equations of motion are reformulated in terms of the principal curvatures of the worldline. It is shown that for arbitrary Lagrangian function ℒ(k1) these equations are completely integrable, i.e., the principal curvatures are defined by integrals. The constants of integration are the particle mass and its spin. The developed method is applied to the study of a model of a relativistic particle with maximal proper acceleration, whose Lagrangian is uniquely determined by a modified form of the invariant relativistic interval. This model gives us an example of a consistent relativistic dynamics obeying the principle of a superiorly limited value of the acceleration, advanced recently.

Relativistic, retardation, and multipole effects in photoionization cross sections: Z, n, and l dependence.

The limits of validity of the nonrelativistic dipole formulation of the total photoionization cross section are explored. Relativistic and nonrelativistic independent particle model calculations of all subshells of C, Sn, and U are performed from 0 to 200 keV above threshold in each case. The comparison shows a remarkable agreement between nonrelativistic dipole and full relativistic multipole results for s subshells, even at the highest energies investigated where nonrelativistic dipole approximation should show significant breakdown; this phenomenon does not occur for l\ensuremath{\ne}0 subshells or in angular distributions. The phenomenon is explained in terms of an approximate cancellation among relativistic, retardation, and multipole effects which occurs only for s subshells.

(2+1)-dimensional models of relativistic particles with curvature and torsion

(2+1)-dimensional models of relativistic particles with the action depending arbitrarily on the world-trajectory curvature and torsion are investigated. A special class of models, described by the action with a maximal symmetry allowing only spin internal degrees of freedom, is singled out. A classical analysis of the systems from this special class is carried out, and the quantization procedure for them is described. Within this class, tachyon-free models are pointed out and the systems having classical and quantum spectra with only massive spin states (whose number in the quantum case may be both finite and infinite) are considered as concrete examples of such models.

Proper BRST quantization of relativistic particles

Recently derived general formal solutions of a BRST quantization on inner product spaces of irreducible Lie group gauge theories are applied to trivial models and relativistic particle models for particles with spin 0, 1 2 and 1 . In the process general quantization rules are discovered which make the formal solutions exact. The treatment also gives evidence that the formal solutions are directly generalizable to theories with graded gauge symmetries. For relativistic particles reasonable results are obtained although there exist no completely Lorentz covariant quantization of the coordinates and momenta on inner product spaces. There are two inequivalent procedures depending on whether or not the time coordinate is quantized with positive or indefinite metric states. The latter is connected to propagators.

Tachyonless models of relativistic particles with curvature and torsion

The problem of constructing (2+1)-dimensional tachyonless models of relativistic particles with an action depending on the world-trajectory curvature and torsion, is investigated. A special class of models, described by a maximal symmetric action and comprising only spin internal degrees of freedom, is found. Examples of systems from the special class are given, whose classical and quantum spectra contain only massive states.

MASSIVE RELATIVISTIC POINT PARTICLE WITH RIGIDITY

The model of relativistic point particle, whose Lagrangian contains a linear dependence on the curvature of the particle world trajectory, is studied. The restriction on the admissible range of parameter α, standing as multiplier α−1 in the Lagrangian term with curvature, is shown to arise in the theory. The general solution of the equations of motion and quantum theory of the system are constructed in the sector with time-like vector of energy-momentum.

MASSLESS POINT PARTICLE WITH RIGIDITY

The model of relativistic particle with rigidity whose action A=−α∫ kds depends on the curvature of particle world trajectory k, is studied. The classical motion of the particle is shown to go along a helical line at superrelativistic velocity and its translational motion along the momentum direction—at the velocity of light (c). After quantization, the parameter a becomes integer, α=n, n>0. The quantum states of the system are massless states of helicities λ=n and λ=−n in which the evolution of gauge-invariant coordinate occurs at velocity c.

CANONICAL QUANTIZATION AND MASS SPECTRUM OF RELATIVISTIC PARTICLE ANALOGUE OF RELATIVISTIC STRING WITH RIGIDITY

The generalized model of relativistic particle is studied. Its action contains the term for a free particle of mass m together with an additional term proportional to the curvature of its world trajectory. From the full set of Hamiltonian constraints, the mass shell condition is singled out and canonical quantization of the model is performed. The quantized system is shown to be equivalent to relativistic rotator with the mass spectrum coinciding with the spectrum of squared Majorana equation: [Formula: see text], where M is rotator’s mass, s is its spin and α−1 is a constant in additional term in action.

Multichiral free superfields with one central charge for N=2,4,6,8.

The N-extended scalar multichiral free superfields, which arise from quantization of a relativistic particle model, are discussed as a representation of N-extended super-Poincar\'e algebra with central charge. Transformation rules for component fields are given and the closure of the algebra is shown.

Dc Electric-Field Enhancement of Cherenkov-Radiation Output Power

The Cherenkov radiation in dielectric-lined waveguide with transverse magnetic (TM) mode coupling has been investigated by using a newly developed relativistic electromagnetic particle model. The parameters used in the simulation are relevant to a recent laboratory experiments. With a 12-A and 220-kV electron beams, the results show that the excited wave is at ω≈ 26 GHz with 310-kW output power. The increase in electron momentum spread is observed to reduce the tightness of electron bunches and to enhance the energy spread of the electrons trapped in the potential well, which results in smaller gain per unit length and reduced nonlinear efficiency. It has also been demonstrated by computer simulations that the output power can be improved by an order of magnitude if in an amplifier configuration the interaction length without phase focusing is doubled and an axial dc electric field (30V/cm) is imposed right before the electron bunches reach the bottom of the potential well.

Relativistic particle models with separable interactions

We present relativistic, classical particle models that possess Poincaré invariance, invariant world lines, particle interaction, and separability.Received 1 April 1982DOI:https://doi.org/10.1103/PhysRevD.26.3482©1982 American Physical Society

General relativity: Dynamics without symmetry

The concept of conditional symmetry is introduced for a parametrized relativistic particle model and generalized to geometrodynamics. Its role in maintaining a one-system interpretation of the quantized theory is emphasized. It is shown that geometrodynamics does not have any conditional symmetry: Such a symmetry should be generated by a dynamical variable K[gab, pab] which is linear and homogeneous in the gravitational momentum pab and which has a weakly vanishing Poisson bracket with the super-Hamiltonian and supermomentum. The generators K fall into equivalence classes modulo the supermomentum constraint. It is shown that each equivalence class can be represented by a member which is a spatial invariant. The remaining weak equations are turned into strong equations by the method of Lagrange multipliers. The local structure of the super-Hamiltonian and supermomentum imposes locality restrictions on the multipliers. These restrictions imply that the generator must be weakly equivalent to a local generator. A recursive argument then shows that the local generator must actually be weakly ultralocal. This uniquely determines the generator as the conformal Killing (super)vector of the local supermetric. However, the curvature scalar in the super-Hamiltonian breaks the conditional symmetry of the supermetric term and turns geometrodynamics into a theory without any symmetry. This result is generalized to inhomogeneous generators.

Form Factor Effect on Photodecay Processes of " " Particles into a Pseudoscalar Meson in a Relativistic Composite Particle Model

Form Factor Effect on Photodecay Processes of " " Particles into a Pseudoscalar Meson in a Relativistic Composite Particle Model

Radiative Decay Spectroscopy of Excited New Mesons Based on a Relativistic Composite Particle Model

Radiative Decay Spectroscopy of Excited New Mesons Based on a Relativistic Composite Particle Model

Current Vertex Functions in the Relativistic Composite Particle Model of Hadrons

Current Vertex Functions in the Relativistic Composite Particle Model of Hadrons

Construction of Pomeron states in the zero-width approximation

We present a kinematical construction for the Pomeron in models of relativistic composite particles in the zero-width approximation.