Target fragmentation in semi-inclusive DIS: Fracture functions, cut vertices and the OPE Original Research Article

We discuss semi-inclusive deep inelastic scattering (DIS) in the z → 1 limit, in particular the relationship between fracture functions, generalised cut vertices and Green functions of the composite operators arising in the OPE. The implications, in the spin-polarised case, for testing whether the “proton spin” effect is target-independent are explored. Explicit calculations in (ƒ3)6 theory are presented which are consistent with our observations.