Electronic correlation spectroscopy in condensed matter

On the basis of formal analysis and the perturbation many-body theory we point out the conditions under which short and long-range electronic correlations in condensed matter can be mapped by means of two-particle coincidence spectroscopy. For particle-impact induced electron emission we show that the coincidence intensity integrated over the slow ejected electron is related to the density-density time correlation function. In the case of a fast incoming and outgoing projectile and a slow emitted electron we relate the intensity to the two-particle and higher order correlations. Erects of two-particle correlations on the two-particle spectral density are investigated by means of the dynamical mean field theory (DMFT) applied to the Hubbard model.