Abstract
Fundamental properties of the position and spin operators in relativistic quantum mechanics are defined with the Poincaré group. Quantum-mechanical counterparts of the classical position and spin variables are the corresponding operators in the Foldy–Wouthuysen representation but not in the Dirac one. The probabilistic interpretation is valid only for Foldy–Wouthuysen wave functions. The relativistic operators of the position and spin are discussed.
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Funding
The work was supported by the National Natural Science Foundation of China (grants no. 12175320, 11975320 and 11805242), the Natural Science Foundation of Guangdong Province, China (grant no. 2022A1515010280), and by the Chinese Academy of Sciences President’s International Fellowship Initiative (grant no. 2019VMA0019). A. J. S. also acknowledges hospitality and support by the Institute of Modern Physics of the Chinese Academy of Sciences.
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Silenko, A.J., Zhang, P. & Zou, L. Poincaré Group and Operators of Position and Spin. Phys. Part. Nuclei 54, 1077–1079 (2023). https://doi.org/10.1134/S1063779623060230
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DOI: https://doi.org/10.1134/S1063779623060230