Single spin asymmetry in inclusive hadron production in pp scattering from Collins mechanism

We study the Collins mechanism contribution to the single transverse spin asymmetry in inclusive hadron production in pp   scattering p↑p→πXp↑p→πX from the leading jet fragmentation. The azimuthal asymmetric distribution of hadron in the jet leads to a single spin asymmetry for the produced hadron in the Lab frame. The effect is evaluated in a transverse momentum dependent model that takes into account the transverse momentum dependence in the fragmentation process. We find the asymmetry is comparable in size to the experimental observation at RHIC at s=200 GeV.