Measurements of the Q2-dependence of the proton and deuteron spin structure functions g1 and g1

The ratio g1F1 has been measured over the range 0.03 < x < 0.6 and 0.3 < Q2 < 10 (GeV/c)2 using deep-inelastic scattering of polarized electrons from polarized protons and deuterons. We find g1F1 to be consistent with no Q2-dependence at fixed x in the deep-inelastic region Q2 > 1 (GeV/c)2. A trend is observed for g1F1 to decrease at lower Q2. Fits to world data with and without a possible Q2-dependence in g1F1 are in agreement with the Bjorken sum rule, but Δq is substantially less than the quark-parton model expectation.