Large enhancement of deuteron polarization with frequency modulated microwaves

10.1016/0168-9002(95)01376-

Measurement of the spin-dependent structure function g1 of the proton

We have measured the spin-dependent structure function g1p of the proton in deep inelastic scattering of polarized muons off polarized protons, in the kinematic range 0.003 < x < 0.7 and 1 GeV2 < Q2 < 60 GeV2. Its first moment, 2b01g1p(x)dx, is found to be 0.136\ub10.011 (stat.)\ub1 0.011 (syst.) at Q2 = 10GeV2. This value is smaller than the prediction of the Ellis-Jaffe sum rule by two standard deviations, and is consistent with previous measurements. A combined analysis of all available proton, deuteron and neutron data confirms the Bjorken sum rule to within 10% of the theoretical valu