M real - Pi // Ox

The incident polarisation vector is chosen parallel to the X axis, i.e. parallel to the scattering vector Q. The direction of the scattered polarisation (in red) is obtained after π-rotation around the magnetic interaction vector Μ (in blue) of the incident polarisation.

The angle of rotation does not depend on the amplitude of the magnetic interaction vector. We can see that the cross-section does not depend on the orientation of the magnetic interaction vector.