  The sensitivity of Circularly polarized X ray Resonant Magnetic Scattering
(CXRMS) to chiral asymmetry has been demonstrated. The study was performed on a
2D array of Permalloy (Py) square nanomagnets of 700 nm lateral size arranged
in a chess lattice of 1000 nm lattice parameter. Previous X ray Magnetic
Circular Dichroism Photoemission Electron microscopy (XMCD-PEEM) images on this
sample showed the formation of vortices at remanence and a preference in their
chiral state. The magnetic hysteresis loops of the array along the diagonal
axis of the squares indicate a non-negligible and anisotropic interaction
between vortices. The intensity of the magnetic scattering using circularly
polarized light along one of the diagonal axes of the square magnets becomes
asymmetric in intensity in the direction transversal to the incident plane at
fields where the vortex states are formed. The asymmetry sign is inverted when
the direction of the applied magnetic field is inverted. The result is the
expected in the presence of an unbalanced chiral distribution. The effect is
observed by CXRMS due to the interference between the charge scattering and the
magnetic scattering.
