  Ott et al. (Science (340, 716 (2013)) successfully transferred Fano profile
into Lorentzian lineshape using an intense infrared laser, after excitation of
autoionizing states in helium by attosecond XUV pulse. This is a very important
step forward of quantum phase control. However, here we show experimentally
that an autoionizing state can have both Fano and Lorentzian behavior
naturally, depending on the process involved. This study utilized the inverse
process of photon absorption ionization, i.e. electron ion recombination with
photon emission, making sure the resonant autoionizing state is not perturbed
by the laser fields. Our result implies that excitation of the state through
different paths can lead to different Fano profiles for the same resonant
state. This allows more options for the combination of laser fields and lead to
more opportunities for quantum phase control. Our result also indicates the
breakdown of the classical two step picture for dielectronic recombination.
