  We present a new theoretical approach to describe X-Ray absorption and
Magnetic Circular Dichroism spectra in the presence of e-e correlation. Our
approach provides an unified picture to include correlations in both charged
and neutral excitations, namely in direct / inversion photoemission where
electrons are removed/added, and photo absorption where electrons are promoted
from core levels to empty states. We apply this approach to the prototypical
case of L$_{2,3}$ edge of 3$d$ transition metals and we show that the inclusion
of many body effects in the core level excitations is essential to reproduce,
together with satellite structures in core level photoemission, the observed
asymmetric line shapes in X-ray absorption and dichroic spectra.
