LAUSR

The hypothesis of quark-hadron duality infers that physical observables of nucleons can be described by a complete set of basis states using either hadronic or quark degrees of freedom. In the EG1b experiment in Hall-B at Jefferson Lab, polarized electrons with energies of 1.6, 2.5, 4.2 and 5.7 GeV were scattered from proton and deuteron targets ($$^{15}\hbox {NH}_3$$15NH3 and $$^{15}\hbox {ND}_3$$15ND3 dynamically polarized along the beam direction) and detected with CEBAF large acceptance spectrometer. Nucleon spin structure functions $$g_1$$g1 and $$g_2$$g2 were measured over a wide kinematic range ($$0.05\,\hbox {GeV}^2< Q^2 <5\,\hbox {GeV}^2$$0.05GeV2