  Definitions of orbital angular momentum based on Wigner distributions are
used to discuss the connection between the Ji definition of the quark orbital
angular momentum and that of Jaffe and Manohar. The difference between these
two definitions can be interpreted as the change in the quark orbital angular
momentum as it leaves the target in a DIS experiment. The mechanism responsible
for that change is similar to the mechanism that causes transverse single-spin
asymmetries in semi-inclusive deep-inelastic scattering.
