Double Transverse Spin Asymmetries at Next-to-leading Order in Qcd

Combined experimental and theoretical efforts in the past few years have led to an improved understanding of the unpolarized parton distributions f(x,Q) and the helicity distributions ∆f(x,Q) of the nucleon. It is known that the complete understanding of the partonic structure of a spin 1 2 object like a nucleon is given in terms of f(x,Q), ∆f(x,Q) and by the transversity distributions δf(x,Q), which give the number densities of partons having the same polarization as the nucleon, when the nucleon is transversely polarized, minus the number with opposite polarization. δf(x,Q) remain quantities about which we have the least knowledge and are at present the focus of much experimental activity. Transversity will be probed in the double transverse spin asymmetries in transversely polarized pp collisions at the BNL Relativistic Heavy Ion Collider (RHIC). The potential of RHIC in accessing transversity through