  Consequences of QCD current algebra formulated on a light-like hyperplane are
derived for the forward scattering of vector and axial-vector currents on an
arbitrary hadronic target. It is shown that current algebra gives rise to a
special class of sum rules that are direct consequences of the independent
chiral symmetry that exists at every point on the two-dimensional transverse
plane orthogonal to the lightlike direction. These sum rules are obtained by
exploiting the closed, infinite-dimensional algebra satisfied by the transverse
moments of null-plane axial-vector and vector charge distributions. In the
special case of a nucleon target, this procedure leads to the Adler-Weisberger,
Gerasimov-Drell-Hearn, Cabbibo-Radicatti and Fubini-Furlan-Rossetti sum rules.
Matching to the dispersion-theoretic language which is usually invoked in
deriving these sum rules, the moment sum rules are shown to be equivalent to
algebraic constraints on forward S-matrix elements in the Regge limit.
