New observables in longitudinal single-spin asymmetries in   semi-inclusive DIS
  We analyze longitudinal beam and target single-spin asymmetries in semi-inclusive deep inelastic scattering and in jet deep inelastic scattering, including all possible twist-3 contributions as well as quark mass corrections. We take into account the path-ordered exponential in the soft correlators and show that it leads to the introduction of a new distribution and a new fragmentation function contributing to the asymmetries. 
Alessandro Bacchetta (1), Piet J. Mulders (2) and Fetze Pijlman (2)   ((1) U. Regensburg, (2) Vrije U. Amsterdam)