Measuring the gluon helicity distribution at a polarized electron-proton collider

A polarized electron-proton collider would offer the opportunity to probe the spin structure of the proton over a greatly enhanced kinematic range compared to earlier fixed-target polarized deep-inelastic scattering experiments. Such a facility would provide access to the gluon helicity distribution within the proton through scaling violations of the polarized structure function, $g_1$, as well as through certain exclusive channels. Estimates of improved constraints on the gluon helicity distribution that could be obtained with a proposed polarized electron-proton collider will be shown.