The missing gauge conditions for the dual fermion emission vertex and their consequences

The authors find that the dual vertex for emitting a ground state fermion of mass m converts between generalized mesonic G gauges and generalized fermionic F gauges. These generalized gauges consist of infinite linear combinations of F's and G's which are, roughly speaking, square roots of Virasoro gauges and exhibit partial reflection and transmission behaviour at the vertex. One of these Ward identities allows us to re-express the amplitude for fermion re- emission in the F/sub 2/ representation where the limit m=0 is well defined. If m=0 and d=10 certain meson channels are saturated by physical (ghost free) states. (12 refs).