[Show abstract][Hide abstract] ABSTRACT: We have measured the proton and deuteron spin structure functions g[sup p][sub 1] and g[sup d][sub 1] in the region of the nucleon resonances for W2 < 5GeV2 and Q2(similar, equals)0.5 and Q2(similar, equals)1.2GeV2 by inelastically scattering 9.7 GeV polarized electrons off polarized 15NH3 and 15ND3 targets. We observe significant structure in g[sup p][sub 1] in the resonance region. We have used the present results, together with the deep-inelastic data at higher W2, to extract Gamma (Q2)(equivalent)01 g1(x,Q2)dx. This is the first information on the low-Q2 evolution of Gamma toward the Gerasimov-Drell-Hearn limit at Q2 = 0.
Full-text · Article · Feb 1997 · Physical Review Letters
[Show abstract][Hide abstract] ABSTRACT: We have measured proton and deuteron virtual photon-nucleon asymmetries A2p and A2d and structure functions g2p and g2d over the range 0.03<x<0.8 and 1.3<Q2<10 (GeV/c)2 by inelastically scattering polarized electrons off polarized ammonia targets. Results for A2 are significantly smaller than the positivity limit sqrt(R) for both targets. Within experimental precision, the g2 data are well-described by the twist-2 contribution g2WW. Twist-3 matrix elements have been extracted and are compared to theorectical predictions.