ALT in the nucleon-nucleon polarized Drell-Yan process Original Research Article

We present a leading order (LO) estimate for the longitidinal-transverse spin asymmetry (Alt) in the nucleon-nucleon polarized Drell-Yan process at RHIC and View the MathML source energies in comparison with All and Alt. Alt receives contribution from g1, the transversity distribution h1, and the twist-3 distributions gt and hl. For the twist-3 contribution we use the bag model prediction evolved to a high energy scale by the large-Nc evolution equation. We found that Alt (normalized by the asymmetry in the parton level) is much smaller than the corresponding Att. Twist-3 contribution given by the bag model turned out to be negligible.