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No abstract available

[en] A theoretical model that predicts the existence of a new vector meson with the mass of M=1100 MeV in the spectrum of the vector mesons was proposed earlier. The main feature of the model is the use of a new type of the potential that binds two quarks inside a meson. The rho-meson excited state spectra and I/PSI particle mass spectrum are considered. All three particles appearing in the mass spectrum of the model exist in nature, provided that the quantum numbers of new vector meson coincide with the quantum numbers of the rho-meson as the model predicts. The model requires more than one (charmed) heavy quark in order to describe the I/PSI particle spectrum

[en] The next-to-leading order QCD analysis of the fragmentation functions obtained from new DELPHI data and the data of other collaborations on the inclusive hadron production e⁺e^-→h+X is performed. The data included into analysis belong to the interval of high momentum transfer: 196 GeV²≤Q²≤8312 GeV² and the value of z(z=E^h/E_beam)>0.18. The number of flavours was taken to be N_f=5. The fit to these data has given the results: Λ(5)/MS=151_-73⁺¹⁰¹ MeV or α_s(M_z²)=0.111_-0.009^+0.009. 22 refs

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[en] The relativistic quasi-potential method of description of states in the quantum field theory is used for studying the spectrum of mesons considered as a bound state of a quark and an artiquark with 1/2 spins. The formulation of the Kadyshevskij quasi-potential equation in the relativistic configuration representation serves as a starting point. It is shown that the extention of the relativistic configuration representation to small distances permits to introduce into consideration a new class of cutoff potentials of quarks by a theoretic group method. The appearance of the quark cutoff potentials in the proposed approach is the consequence of the choice of a new class of unitary irreducible representations of the Lorentz group - the additional series - for the formulation of the quark dynamics. For the explanation of the I/PSI/-particle spectrum in the quark cutoff model considered with the potential of the relativistic Coulomb potential type it is necessary to introduce more than one heavy quark with different masses

No abstract available

[en] The relativistic equation for a system of two particles with spin 1/2 is transformed to a local form in the Lobachevsky momentum space. With the help of the expansion over unitary irreducible representations of the Lorentz group the equation is transformed to a differential-difference equation

[en] In the present paper, physical arguments are given in favour of measuring the fragmentation functions D_q^-h(z,s) in the process e⁺e^-→h+X(h-π, K, p is an identified hadron, X stands for all others) at LEP energies. It is shown that due to the QCD prediction of strong scaling violation in the region of time-like momentum transfers q (q²>0, the channel of the lepton-antilepton annihilation into the hadrons, q²=S), that is essentially more strong than the analogous effect in the space-like region (q²<0, the deep-inelastic lepton-hadron scattering channel, - q²=Q²>0), the study of these fragmentation functions is of great interest. The measurement of the forward-backward asymmetry for hadrons produced in the reaction e⁺e^-→h+X will make it possible to determine the W₃(z,s) structure function that contains the contribution of the neutral quark currents leading to the parity-violation effects. 35 refs.; 8 figs.; 1 tab

[en] The relative motion of quarks is described in the relativistic coordinate space introduced by use of the wave function expansion on the Lorentz group. It is shown that if one includes in this expansion the supplementary series of the unitary representations of the Lorentz groups there naturally appear the potentials that confine quarks