[en] The QCD analysis of the xF₃ structure function measured in deep-inelastic scattering of neutrinos and antineutrinos on an iron target at the Fermilab Tevatron is done in 1-, 2- and 3-loop order of QCD. The x dependence of the higher-twist contribution is evaluated. The experimental value of higher-twist corrections to the Gross-Llewellyn Smith sum rule is discussed. 27 refs., 3 figs., 1 tab

[en] The simultaneous QCD analysis of the xF₃ structure function measured in deep-inelastic scattering by several collaborations is done up to 3-loop order of QCD. The x dependence of the higher-twist contribution is evaluated and turns out to be in a qualitative agreement with the results of 'old' CCFR data analysis and with renormalon approach predictions. The Gross-Llewellyn Smith sum rule and its higher-twist corrections are evaluated. 32 refs., 1 figs., 1 tab

[en] The Thomas-Fermi approach based on the relativistic three-dimensional two-particle quasipotential equation is developed

[en] We compare the higher twist (HT) contribution to the unpolarized structure function F₃ with that one to the nonsinglet combination g₁^p - g₁ⁿ of the polarized proton and neutron structure functions using the assumption that the HT contributions to the Gross-Llewellyn Smith and the Bjorken sum rules are similar. We have found that the relation 1/3x h^xF₃(x) ≅ 6/g_A h^g₁p-g₁n(x) is valid for x≥ 0.1 and for x≥0.2 in the case of LO and NLO QCD approximations, respectively

[en] The deep-inelastic deuteron structure function (SF) F₂^D(x_D,Q²) in the covariant approach in light-cone variables is considered. The x_D and Q²-dependences of SF are calculated. The QCD analysis of generated data both for non-cumulative x_D<1 and cumulative x_D>1 ranges was performed. It was shown that Q²-evolution of SF is valid for ranges 0.275< x_D<0.85 and 1.1< x_D<1.4 for the same value of QCD scale parameter Λ. It was found the x_D-dependence of SF for the ranges is essentially different. 23 refs., 2 figs., 1 tab

[en] The x- and Q²-dependences of the Gottfried sum rule S_G(x,Q²) based on the experimental data on proton and deuteron structure functions are studied. The dependence of S_G(x,Q²) on Q² for low x points to flavour asymmetry of sea quark distributions. For the first time, the coefficients c₁, c₂ of the expansion of S_G(x,Q²) in α_S/π up to the second order are evaluated through the phenomenological analysis of NMC and H1 data. It is found that c₁ is negative while c₂ is positive. The obtained result is in disagreement with QCD predictions for these coefficients. We suggest measuring the low x-dependence of the F₂^D deuteron structure functions at HERA in order to study the Q²-dependence of the Gottfried sum rule. 20 refs., 2 figs., 1 tab

[en] Deep inelastic neutrino-deuteron scattering in the covariant approach in the light-cone variables is considered. The deuteron structure function F₃^D(x,Q²) is calculated in the relativistic impulse approximation on the basis of the relativistic wave function. The results are compared with available experimental data. The nuclear effect of relativistic Fermi motion described by the ratio R_F^D/N = F₃^D/F₃^N is estimated. The dependence of the ratio on x and Q² is investigated. The dependence of the Gross-Llewellyn Smith integral S_GLS(x,Q²) on x and Q² is considered. On the basis of the QCD analysis of the xF₃^N structure function the correction for S_GLS(x,Q²) due to the nuclear effect is estimated and it is shown that the nuclear effect should be taken into account to verify the Gross-Llewellyn Smith sum rule. 25 refs., 4 figs., 2 tabs

[en] The method for the numerical solution of relativistic quasipotential two-particle integral equations in momentum space is developed. For this purpose the method of parabolic splines is used which permits to determine energy eigenvalues and wave functions with suffficient accuracy. As a supplement the masses and wave functions of quarkonium with account for the Coulomb potential dominating at short distances and oscillator blocking at long distances are calculated

[en] A detailed NNLO QCD analysis of new CCFR data on xF₃ structure function including the target mass, higher twist and nuclear corrections was performed and parametrizations of the perturbative and power terms of the structure function were constructed. The results of QCD analysis of the structure function were used to study the Q²-dependence of the Gross-Llewellyn Smith sum rule. The α_S/π-expansion of S_GLS(Q²) was studied and parameters of the expansion were found to be s₁=2.74±0.01, s₂=-2.22±0.23, s₃=-7.86±1.74 which are in good agreement with the perturbative QCD predictions for the Gross-Llewellyn Smith sum rule in the next-to-leading and next-to-next-to-leading order

[en] The formalism for relativistic description of two particles with spin 1/2 is constructed. Used is the two-particle three-dimensional equation, obtained by quasipotential approach. Quasipotential equation in the relativistic configurational space with OBEP potential is reduced to the system of partial equations which is the analog of nonrelativistic Hamada-Jonston system. WKB approach is used to calculate mass spectra and leptonic width of mesons in quark model. The results of the study can be applied to the calculation of mass spectra and widths of electromagnetic decays of systems of e⁺e^-, μ⁺μ^-, c anti c, b anti b, N anti N type