Measurement of the spin-dependent structure function g1(x) of the proton

Adams D, Adeva B, Arik E, et al. Measurement of the spin-dependent structure function g1(x) of the proton. Phys.Lett. B. 1994;329(2-3):399-406.We have measured the spin-dependent structure function $g_1~p$ of the proton in deep inelastic scattering of polarized muons off polarized protons, in the kinematic range $0.003<x<0.7$ and 1\,\mbox{GeV}~2. Its first moment, $\int_0~1 g_1~p(x) dx$, is found to be 0.136 \pm 0.011\,(\mbox{stat.})\pm 0.011\,(\mbox{syst.}) at Q~2=10\,\mbox{GeV}~2. 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 value

Measurement of the spin-dependent structure function g1(x) of the deuteron

Adeva B, Ahmad S, Arvidson A, et al. Measurement of the spin-dependent structure function g1(x) of the deuteron. Phys.Lett. B. 1993;302(4):533-539

Spin Asymmetry in Muon--Proton Deep Inelastic Scattering on a Transversely-Polarized Target

We measured the spin asymmetry in the scattering of 100 GeV longitudinally-polarized muons on transversely polarized protons. The asymmetry was found to be compatible with zero in the kinematic range $0.006<x<0.6$, 1. {}From this result we derive the upper limits for the virtual photon--proton asymmetry $A_2$, and for the spin structure function $g_2$. For $x<0.15$, $A_2$ is significantly smaller than its positivity limit $\sqrt{R}$.Comment: 10 pages CERN-PPE/94-11