We report on the first measurement of the spin-dependent structure function g1d of the deuteron in the deep inelastic scattering of polarised muons off polarised deuterons, in the kinematical range 0.006

We present a measurement of semi-inclusive spin asymmetries for positively and negatively charged hadrons from deep inelastic scattering of polarised muons on polarised protons and deuterons in the range 0:003 < x < 0 : 7. From these asymmetries and the previously published inclusive spin asymmetries we determine, for the rst time, the x-dependent spin distributions for up and down valence quarks and for non-strange sea quarks. We nd that the rst moments of the valence quark Recent results from the polarised inclusive deep inelastic scattering of leptons by protons and deuterons [1,2,3,4,5] show that the quark spins contribute only about 20% to the nucleon spin with a relatively large negative contribution of about 10% from the strange quarks. These conclusions are based on the analysis of the rst moments of the spin-dependent structure functions g 1 (x) of the proton and deuteron in the framework of the quark parton model (QPM). More detailed information on the spin structure of the nucleon can be obtained from polarised semi-inclusive deep inelastic scattering, where in addition to the scattered lepton also hadrons are detected. An early theoretical pre-

We present a new measurement of the spin-dependent structure function g d 1 of the deuteron in deep inelastic scattering of 190 GeV polarised muons on polarised deuterons, in the kinematic range 0:003 < x < 0 : 7 and 1 GeV 2 < Q 2 < 60 GeV 2 . This structure function is found to be negative at small

No abstract

No abstract