Date of Award

Winter 2009

Document Type


Degree Name

Doctor of Philosophy (PhD)



Committee Director

Sebastian E. Kuhn

Committee Member

Gail E. Dodge

Committee Member

Ian Balitsky

Committee Member

Charles I. Sukenik

Committee Member

John Adam


Double spin asymmetries for the proton and the deuteron have been measured in the EG1b experiment using the CLAS detector at Jefferson Lab. Longitudinally polarized electrons at energies 1.6, 2.5, 4.2 and 5.7 GeV were scattered from longitudinally polarized NH3 and ND3 targets. The double spin asymmetry A|| for the proton and the deuteron has been extracted from these data as a function of W and Q2 with unprecedented precision. The virtual photon asymmetry A1 and the spin structure function g1 can be calculated from these measurements by using parametrization to the world data for the virtual photon asymmetry A 2 and the unpolarized structure functions F1 and R. The large kinematic coverage of the experiment (0.05 GeV2 < Q2 < 5.0 GeV2 and 1.08 GeV < W < 3.0 GeV) helps us to better understand the spin structure of the nucleon, especially in the transition region between hadronic and quark-gluon degrees of freedom. The results on A1,g1 and the first moment Γ 1/1 as well as the higher moments Γ 3/1 and Γ5/1, using the entire data set for the deuteron, are presented in this thesis. The moments are compared to theoretical and phenomenological calculations. In addition, parameterizations of the world data on the asymmetries and the spin structure functions are studied to create and refine the models on these quantities that can be used in various applications. Finally, the neutron asymmetries are extracted from the combined proton and deuteron data and the preliminary results are demonstrated.


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