PHENIX Spin Program: Recent results & prospects

The PHENIX spin program utilizes polarized proton collisions in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory to study the spin structure of the proton. We study different aspects of the nucleon spin structure by using longitudinally and transversely polarized beams and measuring single and double asymmetries for a variety of channels (e.g. pions, photons, and muons), primarily at center of mass energies of 200 and similar to 500 GeV. Topics include the measurement of anti-quark helicity distribution functions via W production, the measurement of gluon helicity distribution functions, and the investigation of different mechanisms for the generation of transverse single spin asymmetries. We have reached an era of high enough luminosity and polarization (RHIC-II) to begin our investigation of low cross-section channels, such as the W. In this paper, I present selected recent results and discuss future prospects.