Measurement of the spin structure function GP1 (X, Q2) with CLAS at Jefferson Lab

Inelastic scattering using polarized nucleon targets and polarized charged lepton beams allows the extraction of the structure functions g1 and g2 which provide information on the spin structure of the nucleon. A program designed to study such processes has been underway in Jefferson Lab since 1998. A polarized electron beam, solid polarized NH3 and ND3 targets and the CEBAF Large Acceptance Spectrometer (CLAS) in Hall B were used to collect the desired data. The measurements cover the resonance region with unprecedented detail and add significantly to the DIS data set at low to moderate Q2 and moderate to high x. The measured electron asymmetries are analyzed to produce quantities of interest, such as the photon-nucleon asymmetry AP1+, the spin structure function gP1 and its first moment Gamma1.