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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

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We present the final results of the spin asymmetries A 1 and the spin structure functions g 1 of the proton and the deuteron in the kinematic range 0.0008ϽxϽ0.7 and 0.2ϽQ 2 Ͻ100 GeV 2 . For the determination of A 1 , in addition to the usual method which employs inclusive scattering events and includes a large radiative background at low x, we use a new method which minimizes the radiative background by selecting events with at least one hadron as well as a muon in the final state. We find that this hadron method gives smaller errors for xϽ0.02, so it is combined with the usual method to provide the optimal set of results.

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La section efficace totale inélastique pp est reconstruite pour des valeurs de l'énergie cinétique dans le laboratoire comprises entre 0,3 et 400 GeV. Elle est obtenue par un fit global de la somme des sections efficaces totales pour les canaux inélastiques exclusifs, la somme des sections efficaces topologiques ainsi que des résultats des mesures directes indépendantes. La section efficace inélastique np est reconstruite jusqu'a 4,2 GeV en utilisant la somme des canaux individuels exclusifs et les mesures directes. Les sections efficaces sont décrites par des séries de polynômes de Laguerre généralisés assurant un comportement correct au seuil. Les résultats des fits sont présentés dans des tableaux et sur des figures où ils sont comparés aux données existantes. A partir des dépendances en énergie obtenues pour les sections efficaces totales, on peut déterminer la section efficace totale dans l'état d'isospin I = 0 et tester les prédictions d'invariance d'isospin pour les différents types de réactions. L'accord des données avec les prédictions est étonnamment faible dans le cas des réactions du type NN => NN03C0.

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 0.0031 GeV2. Compared to our previous publication on this subject, with the new data the statistical errors have been reduced by nearly a factor of two. From these asymmetries and our inclusive spin asymmetries we determine the polarised quark distributions of valence quarks and non-strange sea quarks at Q2=10 GeV2. The polarised u valence quark distribution, Δuv(x), is positive and the polarisation increases with x. The polarised d valence quark distribution, Δdv(x), is negative and the non-strange sea distribution, is consistent with zero over the measured range of x

An energy dependent phase-shift analysis is reported for pp, np and pn elastic scattering between 10 and 800 MeV. For the pp case a unique solution smoothly varying with energy is found. A resonant behaviour is observed only in the 1D2 phase shift near the mass 2.14 GeV. For np and pn scattering only a few complex polarization parameters are available ; therefore the solution is less precise, especially above 500 MeV. A fixed-energy analysis at 1 GeV is also reported providing a unique phase-shift set. The formalism, data base and compatibility with other analyses are discussed