Viktor Vasil'evich Andreev

• Professor
• Professor at Francisk Skorina Gomel State University

Form-factor analysis of pseudoscalar π±- and vector ρ±- mesons with zero transmitted momentum has been carried out in the model based on the point form of Poincaré-invariant quantum mechanics. The original method of model parameters’ calculations from leptonic decays π±→ℓ±νℓ± , τ±→ρ±ντ± using pseudoscalar density gπ± constant is proposed. The metho...

In this paper, we obtained a solution for the equation of motion of a charged spinless particle in the field of a plane electromagnetic wave. Relativistic expressions for the cross section of Compton scattering by a charged particle of spin 0 interacting with the field of a plane electromagnetic wave are calculated. Numerical simulation of the tota...

Form-factors investigation of $$\rho ^{\pm }$$ ρ ± –mesons was carried out within the framework of the relativistic quark model, based on point form of Poincaré-invariant quantum mechanics taking into account the internal structure of constituent quarks. It is shown that the parameters of the model obtained from the condition of the agreement of th...

We use special quadrature formulas for singular and hypersingular integral to numerically solve the Schrödinger equation in momentum space with the linear confinement potential, Coulomb and Cornell potentials. It is shown that the eigenvalues of the equation can be calculated with high accuracy, far exceeding other calculation methods. Special meth...

In this paper, we obtained the expected constraints on the anomalous CP-even constants of three-boson interactions on the basis of cross-section for the pair production of W+-bosons in proton-proton collisions. The constraints were obtained for luminosity and the kinematic constraints on the final states typical for the CMS experiment at the Large...

To describe a relativistic hydrogen atom we used the Poincare-covariant model of a two particle system with gauge invariant potential. The kernel of the radial integral equation is obtained which describes a system of two fermions with electromagnetic interaction.

In the course of work, basing on the previously developed method for calculating integral representations of decay constants for pseudoscalar and vector mesons in the frame of point form of Poincare-covariant quark model, the research of ω - and ϕ -mesons decays form-factors for Dalitz V ( q Q ¯ ) → P ( q Q ¯ ) ℓ + ℓ − decays has been carried out....

In the framework of the relativistic quark model based on the point form of the Poincaré-invariant quantum mechanics, the parameters were fixed using the integral representations of the lepton decay constants of pseudoscalar and vector mesons containing u -, d - and s -quarks. As a result of numerical calculations using the oscillator wave function...

The procedure for obtaining the radiative decay constants of pseudoscalar and vector unflavored mesons in the point-form of PiQM is presented. Based on the obtained earlier parameters of the model for light (u, d, s) quarks, we obtain the remaining parameters from the experiments on the V → Py and P → Vy decays. As a result, the mixing angles for p...

The procedure for obtaining the radiative decay constants of pseudoscalar and vector unflavored mesons in point–form of Poincaré-invariant quantum mechanics is presented. In the course of the work the authors determine the remaining parameters from V → P γ and P → V γ experimental decay value, using the obtained earlier parameters of the model for...

The masses of the quarks in the Poincaré-invariant quantum mechanics are the constituent masses. Even in this framework it is possible to obtain an estimate of the constituent quark masses from the Ward identity for the axial current ant the current quark masses.

We use special quadrature formulas for singular and hypersingular integral to numerically solve the Schr\"{o}dinger equation in momentum space with the linear confinement potential, Coulomb and Cornell potentials. It is shown that the eigenvalues of the equation can be calculated with high accuracy, far exceeding other calculation methods. Special...

Mean-square radii and electromagnetic form factors of light mesons are obtained in the framework of Poincare covariant quark model, which is basedon the point form of Poincare invariant quantum mechanics. Calculations areperformed with the use of the requirement of self-consistent description of electroweak properties and masses of pseudoscalar and...

It is shown that the Schrödinger equation in the momentum representation with linear confining potential and Coulomb and Cornell potentials for the states with zero orbital angular momentum can be solved with high accuracy (far superior to other methods) using special quadrature formulas for singular integrals.

This work dedicated to describing two-body compounded system of quarks (meson) in point form of Poincare invariant quantum mechanics with potential, which was offered by so-called Mock-meson model. Authors shows process of calculation the basis parameters of the model by the variational method and followed applications for radiative decay processes...

The paper is obtained that the Schrödinger equation in the momentum representation for a linear confining potential for states with zero orbital angular momentum can be solved with high accuracy (far superior to other methods) using the special quadra-ture formulas for hypersingular integral.

On the basis of a relativistic field-theoretic approach, equations for the interaction of an electromagnetic field with spin 1/2 hadrons have been constructed which take account of polarizabilities and anomalous magnetic moments. With the help of the Green’s function method of solving these equations the Compton scattering amplitude has been calcul...

In the framework of Poincar\'{e} covariant quark model the behavior of running coupling constant $\alpha_{s}\left(Q^{2}\right)$ is considered in $Q < 1 \mbox{GeV}$ region. An analysis was carried out for pseudoscalar and vector mesons with lepton decay constants, masses (obtained from model dependent) and nucleon spin rules required to match their...

A method for deriving invariant amplitudes for Compton scattering in various models and quantum field theories has been proposed which is based on the calculation of matrix elements. The magnetic and electric polarizabilities have been calculated for a spinor particle in QED.Expressions have been derived for the spin polarizabilities gamma_0 and ga...

The behavior of the running coupling constant α s (Q 2) phenomenologically parameterized in the region of Q < 1 GeV is considered within the framework of the Poincare-covariant quark model in a variety of regimes. An analysis was carried out for pseudoscalar and vector mesons with the lepton masses and decay constants (obtained by the model calcula...

We calculated relativistic corrections, which are connected with proton electromagnetic form factors to the energy levels of hydrogen atom with the help of high accuracy technique. To describe a relativistic hydrogen atom we used Poincaré-covariant model of two particle system with a gauge invariant potential. The high-accuracy technique is based o...

A model-independent analysis of anomalous gauge coupling constants of W ± bosons is presented and the corresponding restrictions on them and on the electromagnetic characteristics of W ± bosons following from the experiments on measuring the $ {e^{+} }{e^{-} } \to {W^{+} }{W^{-} } \to \left( {{{e} \left/ {{\mu, \bar{v}}} \right.}} \right) \oplus...

We study the QCD scattering amplitudes for qq → gg and qq → ggg, where q is a massive fermion. Recursive calculational technique based on the method of basis spinors is used.

A method for the calculation of interaction potentials in a momentum space is proposed which is based on exact calculations of the Lorentz structures of the corresponding interaction amplitudes. With this method the kernel of the QCD-motivated potential of a quark-antiquark relativistic system is obtained for different masses and an arbitrary angul...

The electric and magnetic polarizabilities of the charged pion are studied in the framework of the Poincaré-covariant quark model. We consider the pi±-mesons as relativistic two-particle systems with a realistic potential describing the strong interactions between quarks. With the help of the dipole interaction term of bound quark systems in the on...

A method is presented in which matrix elements for some processes are calculated recursively. This recursive calculational technique is based on the method of basis spinors.

The program is presented for analytical calculations of a Quantum Electrodynamics S-matrix as a sum of products of propagators and normal-ordered products of field operators.

A program is described for analytical calculations of the amplitudes of processes involving both massive fermions of arbitrary polarization and massless fermions.

A new method is proposed for calculating amplitudes of processes involving spin-1/2 fermions. The method is based on the use of the isotropic-vierbein vectors in Minkowski space and the basis spinors associated with them. The amplitudes for the electron-positron interaction processes e(-)e(+) -->f (f) over bar and e(-)e(+) --> W-W+ and the amplitud...

The paper presents the new method of calculations of reaction amplitudes of processes with spin 1/2 fermions. The method is based on the application of isotropic tetrad in Minkowski space and basis spinors connected with it. We obtained as test and illustration of the method the amplitudes of interaction processes $e^-e^+\to f \bar{f} $, $e^- e^+\t...

A new method of calculating the amplitudes of processes involving massless fermions with a spin of 1/2 is suggested in the present paper. The method is based on the use of the isotropic tetrad in Minkowski space and the basic spinors related to it. As an illustration, the amplitudes of the electron-positron annihilation into a fermion pair and the...

We present a new variant of the spinor techniques for calculating the amplitudes of processes involving massive fermions with arbitrary polarization. It is relatively simple and leads to basic spinor products. Our procedure is not more complex than CALCUL spinor techniques for massless fermions. We obtain spinor Chisholm identities for massive ferm...

A technique for reducing the matrix elements of the reactions of the interaction of elementary particles with the participation of massive fermions to spinor products is considered. For bispinors describing massive fermions, "spinor" Chisholm identities have been obtained.

In this work a techniques of reduction the matrix element of a process with massive fermions to spinor products is considered. Our procedure is not more complicated than the CALCUL spinor techniques for massless fermions. It is relatively simple and leads to the basic spinor products with arbitrary polarization of fermions. Also we obtained "spinor...

In this work the electromagnetic radius and the polarizability of the mesons are obtained by use of the effective Lagrangians constructed on the one hand with taking into account of general principles of the relativistic quantum field theory and on the other hand with taking into account of the compound relativistic model meson representation. Also...

The leptonic decay constant of the pseudoscalar mesons a calculated by use of the relativistic constituent quark model constructed on the point form of Poincare-covariant quantum mechanics. We discuss the role relativistic corrections for decay constants of pseudoscalar mesons with heavy quarks. We consider the heavy mass limit of decay constant fo...

Using a relativistic constituent quark model based on point form of relativistic quantum mechanics with given set of degrees of freedom we investigate electroweak decays of the pion and rho mesons. All free parameters of quark model (the mass u(d) -quark and parameters which determines the confinement scale) are fixed by using relevant experimental...

We consider a model of meson, based on the Poincare-covariant quark model with analytical solution of the mass spectrum. We investigate possible limitations of model parameters, implied from the lepton decay constants as well as from the mass spectrum of light mesons.

A general approach is proposed that makes it possible to perform a model-independent analysis of C- and P-conserving anomalous three-boson interactions in electron-positron annihilation into a W+W- pair. The cases of both unpolarized and transversely polarized initial beams are considered. The analysis is performed at energies of the LEP 200 machin...

A new method for obtaining model-independent constraints on anomalous three-boson coupling constants in the process e+e- → W+W- is proposed. This method is based on the global analysis of the polarized scattering cross sections for various combinations of initial and final polarization states. The resulting limiting values of the corresponding para...

We evaluate the constraints on anomalous trilinear gauge-boson couplings that can be obtained from the study of electron-positron annihilation into {ital W} pairs at a facility with either the electron beam longitudinally polarized or both electron and positron beams transversely polarized. The energy ranges considered in the analysis are the ones...

The kernel of radial equation for relativistic fermion-fermion system with electromagnetic interaction is calculated exactly with the help of corresponding Feynman diagrams. Radial equation for various types of relativistic corrections in the framework of relativistic Hamilto- nian dynamics is obtained in momentum space. Eigenvalues for various typ...