The Q2 Dependence of the Polarized Structure Functions

A comprehensive program to measure polarized structure functions in the resonance region and beyond using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab has completed taking data. One of the experimental goals is to measure the first moment (Γ1) of the polarized structure function, g1, as a function of Q2 by scattering polarized electrons from polarized proton (NH3) and deuteron (ND3) targets. Deep inelastic scattering measurements obtain positive values for the first moment at large Q2.The first moment is constrained by the Gerasimov-Drell-Hearn sum rule to have a negative slope at the photon point. The CLAS measurements encompass the transition from the low Q2 region dominated by resonances and other non-perturbative effects to the high Q2 region where quasi-free partons dominate the interaction.