  We study the non-singlet sectors of Matrix Quantum Mechanics in application
to two-dimensional string theory. We use the chiral formalism, which operates
directly with incoming and outgoing asymptotic states, related by a scattering
operator. We give a prescription for evaluating the tree level non-singlet
scattering amplitudes given the profile of the Fermi sea. In the case of a
stationary Fermi sea our general formula for the adjoint representation
reproduces Maldacena's scattering amplitude for a long string to go in and come
back to infinity.
