Sivers effect and transverse single spin asymmetries in Drell-Yan   processes
  Sivers asymmetry, adopted to explain transverse single spin asymmetries (SSA) observed in inclusive pion production, p(transv. polarized) p --> pion + X and p-bar(transv. polarized) p --> pion + X is used here to compute SSA in Drell-Yan processes; in this case, by considering the differential cross section in the lepton-pair invariant mass, rapidity and transverse momentum, other mechanisms which may originate SSA cannot contribute. Estimates for RHIC experiments are given. 
M. Anselmino (1), U. D'Alesio (2), F. Murgia (2) ((1) University and   INFN, Torino, Italy, (2) University and INFN, Cagliar...