  Doubly-excited Rydberg states of helium (He) nanodroplets have been studied
using synchrotron radiation. We observed Fano resonances related to the atomic
N = 2,0 series as a function of droplet size. Although similar qualitatively to
their atomic counterparts, the resonance lines are broader and exhibit a shift
in energy which increases for the higher excited states. Furthermore,
additional resonances are observed which are not seen in atomic systems. We
discuss these features in terms of delocalized atomic states perturbed by the
surrounding He atoms and compare to singly excited droplets.
