Measurements of the proton and deuteron spin structure functions g(1) and g(2) - art. no. 112003

Measurements are reported of the proton and deuteron spin structure functio ns g(1)(p) and g(1)(d) at beam energies of 29.1, 16.2., and 9.7 GeV, and g( 2)(p) and g(2)(d) at a beam energy of 29.1 GeV. The integrals Gamma(p) = in tegral(0)(1)g(1)(p)(x, Q(2))dx and Gamma(d) = integral(0)(1)g(1)(d)(x, Q(2) )dx were evaluated at fixed Q(2) = 3 (GeV/c)(2) using the full data set to yield Gamma(p) = 0.132+/-0.003(stat)+/-0.009(syst) and Gamma(d)=0.047+/-0.0 03+/-0.006. The Q(2) dependence of the ratio g(1)/F-1 was studied and found to be small for Q(2) > 1 (GeV/c)(2). Within experimental precision the g(2 ) data are well described by the twist-2 contribution, g(2)(WW). Twist-3 ma trix elements were extracted and compared to theoretical predictions. The a symmetry A(2) was measured and found to be significantly smaller than the p ositivity limit root R for both proton and deuteron targets. A(2)(p) is fou nd to be positive and inconsistent with zero. Measurements of g(1) in the r esonance region show strong variations with x and Q2, consistent with reson ant amplitudes extracted from unpolarized data. These data allow us to stud y the Q(2) dependence of the integrals Gamma(p) and Gamma(n) below the scal ing region. [S0556-2821(98)06919-7].