Transverse Single Spin Asymmetries in Hadronic Interactions: an   experimental overview and outlook
  Transverse single-spin asymmetries (SSA) are expected to be small in perturbative QCD because of the chiral nature of the theory. Experiment shows large transverse SSA for particle produced in special kinematics. This contribution reviews the experimental situation and provide an outlook for future measurements. 
L.C. Bland
hep-ex hep-ph