Inclusive ALL Measurements at STAR
Abstract
One of the primary goals of the RHIC Spin program is to determine the gluon polarization distribution within the proton. At leading order, pp collisions involve a mixture of quark-quark, quark-gluon, and gluon-gluon scattering. In RHIC, the gluon-gluon and quark-gluon contributions dominate, making the accelerator an ideal tool to explore gluon polarization. The STAR experiment has measured the longitudinal double-spin asymmetry ALL for inclusive production of jets and pions, and for charged pion production opposite a jet, at s = 200 GeV. The results provide valuable new constraints on the gluon polarization in the proton when included in a next-to-leading-order global analysis. The current status of the STAR measurements and the plans for future measurements will be discussed.