Measurements are reported of the proton and deuteron spin structure functions gp1 and gd1 at beam energies of 29.1, 16.2, and 9.7 GeV, and gp2 and gd2 at a beam energy of 29.1 GeV. The integrals Γp = ∫10gp1(x,Q2)dx and Γd = ∫10gd1(x,Q2)dx were evaluated at fixed Q2 = 3(GeV/c)2 using the full data set to yield Γp = 0.132±0.003(stat)±0.009(syst) and Γd = 0.047±0.003±0.006. The Q2 dependence of the ratio g1/F1 was studied and found to be small for Q2 > 1 (GeV/c)2. Within experimental precision the g2 data are well described by the twist-2 contribution, gWW2. Twist-3 matrix elements were extracted and compared to theoretical predictions. The asymmetry A2 was measured and found to be significantly smaller than the positivity limit √R for both proton and deuteron targets. Ap2 is found to be positive and inconsistent with zero. Measurements of g1 in the resonance region show strong variations with x and Q2, consistent with resonant amplitudes exited from unpolarized data. These data allow us to study the Q2 dependence of the integrals Γp and Γn below the scaling region.
|Journal||Physical Review D - Particles, Fields, Gravitation and Cosmology|
|Publication status||Published - 1998 Dec 1|
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)