  We express all equivariant Gromov-Witten invariants of the projective line as
matrix elements of explicit operators acting in the Fock space. As a
consequence, we prove the equivariant theory is governed by the 2-Toda
hierarchy of Ueno and Takasaki. This is the second in a sequence of three
papers devoted to the Gromov-Witten theory of nonsingular target curves (the
first paper of the series is math.AG/0204305).
