  We study the contribution of the collinear twist-3 quark-gluon correlation to
the single transverse-spin asymmetry in direct-photon and single-jet
productions in pp collision. At typical RHIC kinematics we find sizable
asymmetries in the forward region of the polarized nucleon while they are
almost zero in the backward region. We also find the soft-fermion pole
contribution is vanishingly small, suggesting the measurement of these
asymmetries provides us with an unique opportunity to determine the net
soft-gluon pole function.
