Relativistic Position Operator for Free Particles
- 1 October 1963
- journal article
- research article
- Published by AIP Publishing in Journal of Mathematical Physics
- Vol. 4 (10) , 1223-1228
- https://doi.org/10.1063/1.1703893
Abstract
Certain definitions and derivations for the relativistic center of mass are considered and are related to the position operator corresponding to the representation proposed in a previous paper. It is shown that the classical definition of Pryce has indeed a more direct correspondence with our representation than the Foldy‐Wouthuysen representation, in spite of the fact that Pryce's particular method of symmetrization leads to the latter. In the process of derivation, the points of view of Synge, Pryce, and Shirokov are compared and the expressions for the velocity and the intrinsic angular momentum corresponding to the different definitions are given. In the Appendix, our operator is compared with that of Newton and Wigner for the case of spin ½.Keywords
This publication has 4 references indexed in Scilit:
- Canonical Form of the Covariant Free-Particle EquationsJournal of Mathematical Physics, 1963
- On the Dirac Theory of Spin 1/2 Particles and Its Non-Relativistic LimitPhysical Review B, 1950
- Localized States for Elementary SystemsReviews of Modern Physics, 1949
- The mass-centre in the restricted theory of relativity and its connexion with the quantum theory of elementary particlesProceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, 1948