  We analyze the influence of a local pairing on the quantum interference in
nanoscopic systems. As a model system we choose the double quantum dot coupled
to one metallic and one superconducting electrode in the T-shape geometry. The
analysis is particularly valuable for systems containing coupled objects with
considerably different broadening of energy levels. In such systems, the
scattering of itinerant electrons on a discrete (or narrow) energy level gives
rise to the Fano-type interference. Systems with induced superconducting order,
along well understood Fano resonances, exhibit also another features on the
opposite side of the Fermi level. The lineshape of these resonances differs
significantly from their reflection on the opposite side of the Fermi level,
and their origin was not fully understood. Here, considering the spin-polarized
tunneling model, we explain a microscopic mechanism of a formation of these
resonances and discuss the nature of their uncommon lineshapes. We show that
the anomalous Fano profiles originate solely from the pairing of nonscattered
electrons with scattered ones. We investigate also the interplay of each type
of resonances with the Kondo physics and discuss the resonant features in
differential conductivity.
