First JAM results on the determination of polarized parton distributions

The Jefferson Lab Angular Momentum (JAM) collaboration is a new initiative aimed at the study of the angular-momentum-dependent structure of the nucleon. First results on the determination of spin-dependent parton distribution functions from world data on polarized deep-inelastic scattering will be presented and compared with previous determinations from other groups. Different aspects of global QCD analysis will be discussed, including effects due to the nuclear structure of deuteron and Helium targets, target-mass corrections and higher twist contributions to the g1 structure function as well as the g2 structure function.