  We show that the so-called "trion line" in the absorption spectrum of doped
quantum wells, comes from a singular many-body object, intrinsically wide in
energy: the photocreated virtual exciton dressed by Coulomb and Pauli
interactions with the well carriers. This understanding is supported by the
spectra of circular dichroism obtained with a spin-polarized Fermi sea: the
sharp edge on the low-energy side and the significant tail at high energies are
well explained by these many-body effects, not by bound 3-body trions.
