SPIN IN CLASSICAL AND QUANTUM THEORY

Journal Article · Wed Mar 15 04:00:00 EST 1961 · Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D

DOI:https://doi.org/10.1103/PhysRev.121.1833· OSTI ID:4049332

Corben, H C

The classical equations of motion of a charged pointparticle with intrinsic spin under the influence of an external electromagnetic field are restated and compared with the Heisenberg equations of motion derived from the Dirac theory. The partition of angular momentum between particle and field in the classical theory is contrasted to the Dirac theory of electron spin. The analogy between the Dirac equation and the theory of parametric amplification is pointed out. A free spinning point particle moving according to the laws of classical relativistic point-particle mechanics may move along a helix. The sum of the intrinsic spin sigma and the angular momentum of the helical motion in this classical analog of zitterbewegung is an effective spin vector S which is a constant of the motion. Because of this internal motion, the effective mass M of the particle differs from the mass m which is ascribed to it in the equations of motion. Solutions are found in which S is parallel or antiparallel to the momentum, and the sign of M is determined by the helicity. When placed in a uniform electromagnetic field, the particle behaves as if it had a rest mass M and a magnetic moment e sigma /Mc, in addition to any explicit magnetic moment that may be ascribed to it. (auth)

• Research Organization: Space Tech. Labs., Los Angeles
• NSA Number: NSA-15-015198
• OSTI ID: 4049332
• Journal Information: Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D, Journal Name: Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D Vol. Vol: 121; ISSN PHRVA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ANGULAR DISTRIBUTION
DIRAC EQUATIONS
ELECTRIC CHARGES
ELECTROMAGNETIC FIELDS
ELECTRONS
EQUATIONS
FIELD THEORY
MAGNETIC MOMENTS
MASS
MOMENTUM
MOTION
OSCILLATIONS
PARTICLES
PHYSICS
QUANTUM MECHANICS
RELATIVITY THEORY
SPIN
VECTORS
ZITTERBEWEGUNG