11 research outputs found
Spinning Particles on Spacelike Hypersurfaces and their Rest-Frame Description
A new spinning particle with a definite sign of the energy is defined on
spacelike hypersurfaces after a critical discussion of the standard spinning
particles. They are the pseudoclassical basis of the positive energy [or negative energy ] parts of the solutions of the Dirac equation. The study of the isolated system of N
such spinning charged particles plus the electromagnetic field leads to their
description in the rest-frame Wigner-covariant instant form of dynamics on the
Wigner hyperplanes orthogonal to the total 4-momentum of the isolated system
(when it is timelike). We find that on such hyperplanes these spinning
particles have a nonminimal coupling only of the type "spin-magnetic field"
like the nonrelativistic Pauli particles to which they tend in the
nonrelativistic limit. The Lienard-Wiechert potentials associated with these
charged spinning particles are found. Then, a comment on how to quantize the
spinning particles respecting their fibered structure describing the spin
structure is done.Comment: 70 pages, revte
Relativistic Operator Description of Photon Polarization
We present an operator approach to the description of photon polarization,
based on Wigner's concept of elementary relativistic systems. The theory of
unitary representations of the Poincare group, and of parity, are exploited to
construct spinlike operators acting on the polarization states of a photon at
each fixed energy momentum. The nontrivial topological features of these
representations relevant for massless particles, and the departures from the
treatment of massive finite spin representations, are highlighted and
addressed.Comment: Revtex 9 page