Neutron Scatterings Resulting in Half Moons and Pinch Points

Left panels: Spin (atomic magnet) configurations respecting (lower panel) and violating (upper panel) the conservation law.

Right panels: The corresponding neutron scatterings for the two situations: 3D structure of the neutron scattering pattern (mid panel) and the constant energy cross sections of the pinch point (lower panel) and half moon (upper panel). The two patterns corresponding to the two spin configurations on the left.