Sivers Effect for Pion and Kaon Production in Semi-Inclusive Deep   Inelastic Scattering
  We study the Sivers effect in the transverse single spin asymmetries (SSA) for pion and kaon production in semi-inclusive deep inelastic scattering (SIDIS) processes. We perform a fit of A^sin(phi_h-phi_S)_UT which, by including recent high statistics experimental data for pion and kaon production from HERMES and COMPASS Collaborations, allows a new determination of the Sivers distribution functions for quarks and antiquarks with u, d and s flavours. Estimates for forthcoming SIDIS experiments at COMPASS and JLab are given. 
M. Anselmino, M. Boglione, U. D'Alesio, A. Kotzinian, S. Melis, F.   Murgia, A. Prokudin and C. Turk