The RHIC Spin Program: Snapshots of Progress

TL;DR

This paper reviews progress in polarized proton collision experiments at RHIC, highlighting tools, detector complementarity, and the potential to determine gluonic contributions to proton spin within the next decade.

Contribution

It summarizes experimental developments and emphasizes RHIC's unique role in measuring the gluonic contribution to proton spin and testing QCD spin predictions.

Findings

Development of experimental tools for polarized proton collisions

Complementary roles of PHENIX and STAR detectors

RHIC's potential to determine gluonic spin contribution

Abstract

I review progress toward the experimental study of polarized proton collisions at RHIC, at center-of-mass energies of several hundred GeV. The tools under development for these experiments are summarized, with emphasis on the complementarity for the spin program of the two major detectors, PHENIX and STAR. The proposed research program includes measurements of the spin structure of hadrons, tests of QCD predictions for spin observables, and polarization searches for interactions beyond the Standard Model. I argue, in particular, that RHIC should provide the best determination of the gluonic contribution to proton spin foreseen for the coming decade.