A_N in inclusive lepton-proton collisions

Some estimates for the transverse single spin asymmetry, A_N, in the inclusive processes l p(transv. pol.) -> h X are compared with new experimental data. The calculations are based on the Sivers and Collins functions as extracted from SIDIS azimuthal asymmetries, within a transverse momentum dependent factorization approach. The values of A_N thus obtained agree in sign and shape with the data. Predictions for future experiments are also given.