  We study the transverse single spin asymmetry (SSA), A_N, for the single
inclusive process l p (transv. polarized) --> h + X, in a perturbative QCD
factorization scheme with inclusion of spin and transverse momentum dependent
(TMD) distributions. By adopting the relevant TMDs (Sivers and Collins
functions) as extracted from semi-inclusive deep inelastic scattering (SIDIS)
and e+e- data, predictions for these SSAs are given. A measurement of A_N for
this process could then provide a direct test of the validity of the TMD
factorization.
