PHYSICAL REVIEW C
We present the results of our final analysis of the full data set of g(1)(p) (Q(2)), the spin structure function of the proton, collected using CLAS at Jefferson Laboratory in 2000-2001. Polarized electrons with energies of 1.6, 2.5, 4.2, and 5.7 GeV were scattered from proton targets ((NH3)-N-15 dynamically polarized along the beam direction) and detected with CLAS. From the measured double spin asymmetries, we extracted virtual photon asymmetries A(1)(p) and A(2)(p) and spin structure functions g(1)(p) and g(2)(p) over a wide kinematic range (0.05 GeV2 < Q(2) < 5 GeV2 and 1.08 GeV< W < 3 GeV) and calculated moments of g(1)(p). We compare our final results with various theoretical models and expectations, as well as with parametrizations of the world data. Our data, with their precision and dense kinematic coverage, are able to constrain fits of polarized parton distributions, test pQCD predictions for quark polarizations at large x, offer a better understanding of quark-hadron duality, and provide more precise values of higher twist matrix elements in the framework of the operator product expansion.
Fersch, R. G.; Guler, N.; Bosted, P.; Deur, A.; Griffioen, K.; Keith, C.; Kuhn, S. E.; Minehart, R.; Prok, Y.; Adhikari, K. P.; Adhikari, S.; Akbar, Z.; Amaryan, M. J.; Pereira, S. Anefalos; Asryan, G.; Avakian, H.; Ball, J.; Balossino, I.; Baltzell, N. A.; Dashyan, N.; Ghandilyan, Y.; Hakobyan, H.; Khachatryan, G.; Simonyan, A.; and Voskanyan, H., Determination of the proton spin structure functions for 0.05 < Q(2) < 5GeV(2) using CLAS (2017). PHYSICAL REVIEW C, 96(6).