[en] Results are presented on inelastic J/ψ-production from muon interactions with hydrogen, deuterium, carbon and tin. The data were collected by the experiment NA37 at the CERN SPS. The measured cross section ratio per nucleon for muon-induced J/ψ-production in deuterium and hydrogen was found to be R(D₂/H₂)=1.01±0.15. The Colour Singlet model is shown to provide a good description of the observed differential cross section apart from a normalisation factor. The comparison between the observed cross section and the Colour Singlet model prediction allows the extraction of the gluon structure function G(x) of the nucleon. The momentum fraction x of the nucleon carried by the gluon is measured in the range of x=[0.02,0.3]. The cross section ratio per nucleon for carbon and tin was studied as a function of the energy fraction z, taken by the J/ψ-meson and its squared transverse momentum, P_T². (author) 11 refs., 8 figs

[en] The results of the New Muon Collaboration measurements of deep inelastic muon scattering on hydrogen and deuterium are presented. The data extend the range of previous measurements towards low x. They are in good agreement with the SLAC and BCDMS results and show differences with respect to the EMC ones. At low x these data are not described by existing parton parametrisations. Next-to-leading order QCD analysis of NMC data is presented. The mesured scaling violations in F₂ are in good agreement with perturbative QCD. The flavour singlet and non-singlet quark distributions as well as gulon distribution are extracted. (orig.)

[en] In this paper the status of structure functions F₂(x_Bj,Q²) and R(x_Bj,Q²) from different experiments and their consistency is discussed. Results on the ratio of neutron to proton structure functions and its implications are presented. Short discussion of Λ_QCD determinations as well as quark and gluon parameterizations are also included

No abstract available

[en] The New Muon Collaboration (NMC) has measured cross sections of deep inelastic muon scattering on the proton and the deuteron at incident muon energies of 90, 120, 200 and 280 GeV. The data cover a wide kinematic range of 0.002< x<0.60 and 0.5< Q²<75 GeV². The F₂ results arecompared with those from other fixed target experiments as well as with recently published HERA data on F₂ from 1994 run. The agreement is good. In the kinematic range covered by our data, the cross section is sensitive to R for 0.0045≤x≤0.12. Therefore R could be extracted in this x range, thereby extending the domain where R is measured and improving the precision in the region of overlap with earlier CDHSW measurements. The difference R^d-R^p was determined from cross section ratio and found compatible with zero. The structure functions F₂ were also obtained by using the parametrisation of R(R₁₉₉₀) from SLAC. This parametrisation is in reasonable agreement with the present data for R. They are also compatible with a perturbative QCD predictions for R calculated with recent parametrisations of parton distributions. (orig.)

[en] The results of the New Muon Collaboration measurements of deep inelastic muon scattering on hydrogen and deuterium are presented. The data extend the range of previous measurements towards low x. They are in good agreement with the SLAC and BCDMS results and show differences with respect to the EMC ones. At low x these data are not described by existing parton parametrizations. The Gottfried sum calculated from these data agrees with the previously published NMC result and is significantly lower than 1/3, the value expected for a flavor symmetric sea, and agrees with the previously published NMC result. The difference between the ratio of longitudinally to transversely polarized virtual photon cross sections for the deuteron and proton, R^d-R^p, is consistent with zero down to x=0.01

[en] Properties of hadron multiplicities in 280 GeV μ⁺p interactions have been investigated. The c. m. energy dependence in the range from 4 to 20 GeV as well as variation with Q² are presented. No variation faster than logarithmic is seem in the energy range of this experiment. Increases in both the mean charged hadron multiplicity and the K⁰ yield are observed with increasing Q² for fixed c. m. energy W. The detailed study of fragmentation function shows that extra particles are produced mainly in the central region of x_F. 6 refs., 7 figs. (author)

[en] The QCD analysis of the F^p₂ and F^d₂ structure functions obtained by New Muon Collaboration is presented. It leads to precise determination of the gluon distribution down to x=0.008. The re-evaluation of the Gottfried sum, i.e., the integral ∫(F^p₂-Fⁿ₂)dx/x,based on better knowledge of the F^d₂ at low x, gives at Q²=4 GeV² value 0.235±0.026(total), significantly smaller than 1/3. This result can be interpreted as flavor symmetry violation in the nucleon sea. Similar conclusion was reached from the analysis of Drell-Yan asymmetry measured by NA51 experiment at CERN. copyright 1995 American Institute of Physics

[en] The results of the study of the ratio γ of Σ^-π⁺ to Σ⁺π^- production in K^-p interaction at the threshold and above averaged the region from 140 to 250 MeV/c of the incident kaon momentum are presented. The values of this ratio at rest and in flight were found to be 2.37+-0.05 and 1.12+-0.05 respectively. The analysis also yields a value 0.477+-0.008 for the hyperon Σ⁺ decay into π⁺n branching ratio. (author)

[en] Experimental results of deep inelastic scattering of polarized leptons from polarized target nucleons are reviewed. Accurate values of the spin dependent structure function g₁(x) were obtained in those experiments covering a large kinematic range. The combination of all experimental results confirms the validity of the Bjorken sum rule. (author)