Theory of resonant Raman scattering from intra- and inter-band collective excitations in two-band quantum wires.

We develop a theory for the collective excitations in a quantum wire with t wo occupied subbands. The dispersion relations of the intra- and inter-subb and spin and charge modes are determined as a function of the interaction s trength. The hitherto unexplained "single particle excitations", which appe ar near resonance, independently of the relative polarization of incoming a nd outgoing light, are shown to originate from higher order spin density ex citations.