Angular momentum nonconservation and conservation in quasiclassical Positronium

TL;DR

This paper investigates how Thomas precession affects angular momentum conservation in a quasiclassical Positronium model, revealing specific conditions under which angular momentum remains conserved despite no external torque.

Contribution

It identifies the precise conditions involving intrinsic angular momentum components that determine angular momentum conservation in a quasiclassical Positronium model.

Findings

Angular momentum is not generally conserved due to Thomas precession.

Conservation occurs only when intrinsic angular momenta are antiparallel and equal in magnitude.

The model clarifies the role of intrinsic spins in angular momentum dynamics.

Abstract

It is shown that due to Thomas precession, angular momentum is not generally a constant of the motion in a quasiclassical model of the Positronium atom consisting of circular-orbiting point charges with intrinsic spin and associated magnetic moment. Despite absence of externally-applied torque, angular momentum is a constant of the motion only if the electron and positron intrinsic angular momentum vector components perpendicular to the orbital angular momentum are antiparallel and of equal magnitude.