The magnetic moment of a gyrating particle is μ μ = γ γ m 0 v ⊥ ⊥ 2 2 B , which respects special relativity. γ γ is the relativistic Lorentz factor, m 0 is the rest mass, v ⊥ ⊥ is the velocity perpendicular to the magnetic field, and B is the magnitude of the magnetic field.