It is well known that in open quantum systems resonances can coalesce at an
exceptional point, where both the energies {\em and} the wave functions
coincide. In contrast to the usual behaviour of the scattering amplitude at one
resonance, the coalescence of two resonances invokes a pole of second order in
the Green's function, in addition to the usual first order pole. We show that
the interference due to the two pole terms of different order gives rise to
patterns in the scattering cross section which closely resemble Fano-Feshbach
resonances. We demonstrate this by extending previous work on the analogy of
Fano-Feshbach resonances to classical resonances in a system of two driven
coupled damped harmonic oscillators.Comment: 8 pages, 5 figures, submitted to J. Phys.
