  We present a new analysis for the single-transverse spin asymmetry (SSA) for
the inclusive pion and kaon productions in the proton-proton collisions
measured at RHIC. The framework we use is the collinear factorization in which
SSA appears as a twist-3 observable resulting from the multiparton correlations
in the hadrons. As a relevant multiparton correlation, we include all the
contributions associated with the quark-gluon correlation functions in the
transversely polarized proton, i.e., those from the soft-gluon-pole (SGP) and
the soft-fermion-pole (SFP). We have found that the SGP contribution alone is
insufficient to describe the observed RHIC A_N data and the inclusion of the
SFP contribution plays an important role for the improved description of the
data. In particular, P_T-dependence of A_N and A_N for K^- have been well
described in our new analysis.
