 Gyromagnetic-ratio assumption in higher-spin magnetic spectra

The scalar and Dirac magnetic spectra do not determine every higher-spin spectrum. Extrapolating to $E^2=m^2{c}^4+p_z^2{c}^2+|e|\hslash |B|c(2n+1-2m_s)$ assumes gyromagnetic ratio two. For a spin-one field with that coupling the lowest aligned mode becomes unstable once its squared frequency turns negative; spin alone does not imply this coupling.