2019/03/18 by Evgeni Saldin, Saldin, Evgeni
Engineering · Physics and Astronomy · #Accelerator Physics (physics.acc-ph) #Astronomical Observations and Instrumentation #Classical Physics (physics.class-ph) #FOS: Physical sciences #History and Developments in Astronomy #Relativity and Gravitational Theory
paper · pdf · doi:10.48550/arxiv.1903.07452
openalex publication_date 2019/03/18 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The standard expression for the Wigner rotation leads to incorrect result for\nthe wavefront rotation. The results for the Wigner rotation in the Lorentz lab\nframe obtained by many experts on special relativity such as Moeller and\nJackson, are incorrect. They overestimate the angle of the Wigner rotation by a\nfactor \γ compared to its real value, and the direction of the rotation\nis also determined incorrectly. In 1959, Bargman, Michel, and Telegdi (BMT)\nproposed a consistent relativistic theory for the dynamics of the spin as\nobserved in the lab frame, which was successfully tested in experiments. The\nBMT equation naturally involves the Wigner rotation as the purely kinematic\naddition to the Larmor rotation which, in turn, is a consequence of interaction\nof the intrinsic magnetic moment with the external magnetic field. It is\ncommonly believed that the BMT equation contains the standard (and incorrect)\nresult for the Wigner rotation in the Lorentz lab frame. The existing textbooks\nthen suggest that the experimental test of the BMT equation is a direct proof\nof validity for the standard expression for Wigner rotation. Here we focus on\nthe analysis of the reason why authors of textbooks obtained an incorrect\nexpression for the Wigner rotation. We demonstrate that the notion that the\nstandard (incorrect) result for the Wigner rotation as an integral part of the\nBMT equation in most texts is based, in turn, on an incorrect physical\nargument. The aim of the present paper is to analyze the complicated situation\nrelating to the use of the theory of relativity and, in particular, Wigner\nrotation theory, in accelerator physics.\n