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V. V. Burov

Publications and source records attributed to V. V. Burov.

29 records · Page 2Linked to original sources

Separable Kernel of Nucleon-Nucleon Interaction in the Bethe-Salpeter Approach for J=0,1

The solution for the nucleon-nucleon T matrix in the framework of the covariant Bethe-Salpeter approach for a two spin-one-half particle system with a separable kernel of interaction is analyzed. The explicit analytical connection between parameters of the separable kernel and low energy scattering parameters, deuteron binding energy and phase shifts is established.Covariant separable kernels for positive-energy partial channels with total angular momentum J=0 (1S0+, 3P0+) and J=1 (3S1+-3D1+, 1P1+, 3P1+) are constructed by using obtained relations.

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Bethe-Salpeter approach with the separable interaction for the deuteron

Recent developments of the covariant Bethe-Salpeter (BS) approach with the use of the separable interaction for the deuteron are reviewed. It is shown that the BS formalism allows a covariant description of various electromagnetic reactions like the lepton-deuteron scattering, deuteron electro-disintegration, deep inelastic scattering (DIS) of leptons on light nuclei. The procedure of the construction of the separable nucleon-nucleon (NN) interaction is discussed. The BS formalism facilitates analysis of the role of the P-waves (negative energy components) in the electromagnetic properties of the deuteron and its comparison with the nonrelativistic results. Furthermore the covariant BS approach makes it possible to analyze DIS of leptons from the deuteron in a model independent way and to extend the formalism to DIS reactions on the light nuclei.

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Evolution of the nucleon structure in the lightest nuclei

The evolution of the nucleon structure as a function of atomic mass A is considered for the first time for the lightest nuclei, D, 3H, 3He and 4He, with an approach based on the Bethe-Salpeter formalism. We show that the pattern of the oscillation of the structure functions ratio r^A(x) = F_2^A/F_2^N(D) varies with A by changing the position of the cross-over point x_3 in which r^A(x) = 1, unlike the pattern for nuclei with masses A larger than 4, where only the amplitude of the oscillation changes. In particular we find that the pattern of F_2(x) modifications is controlled with the values (1 - x_3) = 0.32 (D/N), 0.16 (3He/D) and 0.08 (4He/D). The obtained results follow from the relativistic consideration of the nuclear structure and allow us to define a whole class of modifications of the partonic distributions in the nucleon bound in a nucleus. The EMC effect is explained as a particular case of the considered class.

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Light-front versus Bethe-Salpeter forms of two nucleon amplitudes

We discuss the relation between the two nucleon Bethe-Salpeter amplitude and the light front wave functions. Both approaches provide a covariant description for the deuteron bound state and the two nucleon scattering state. A comparison is done for the spin-orbit functions as well explicit integrals are given on the basis of the Nakanishi integral representation method.

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Evolution of the EMC Effect in Light Nuclei

The evolution of the EMC effect as a function of atomic mass $A$ is considered for the first time for the lightest nuclei, D, $^3H$, $^3He$ and $^4He$, with an approach based on the Bethe-Salpeter formalism. We show that the pattern of the oscillation of the ratio $r^A(x) = F_2^A/F_2^N(D)$ varies with $A$, unlike the pattern for nuclei with masses $A > 4$, where only the amplitude of the oscillation changes.

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On isovector meson exchange currents in the Bethe-Salpeter approach

We investigate the nonrelativistic reduction of the Bethe-Salpeter amplitude for the deuteron electrodisintegration near threshold energies. To this end, two assumptions have been used in the calculations: 1) the static approximation and 2) the one iteration approximation. Within these assumptions it is possible to recover the nonrelativistic result including a systematic extension to relativistic corrections. We find that the so-called pair current term can be constructed from the $P$-wave contribution of the deuteron Bethe-Salpeter amplitude. The form factor that enters into the calculation of the pair current is constrained by the manifestly gauge independent matrix elements.

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Deuteron electrodisintegration near threshold in the Bethe-Salpeter approach

In the framework of the covariant Bethe-Salpeter formalism we calculate the amplitude of electrodisintegration of the deuteron near the threshold energy. Due to the small relative momentum of the final np-pair, the deuteron break-up process may be sufficiently described by a transition to the dominant 1S0 channel into the final state. Therefore only one unknown structure function (form factor) exists. The explicit formula for this form factor is given in terms of partial Bethe-Salpeter amplitudes. We compare our result to the usual non-relativistic calculations. The essential role of P-states as well as their possible link to mesonic exchange currents is discussed.

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Can we learn anything new from polarization observables of the deuteron disintegration near threshold?

We discuss polarization characteristics of the deuteron disintegration near the threshold energy. Due to the small relative energy of the outgoing $np$ pair, the dominant amplitude for this process is a 1+ -> 0^+ transition. Relativistic covariance requires only one electromagnetic transition form factor for this amplitude. Subsequently this leads to substantial simplifications in the formulas of the polarization observables and allows to draw conclusions independent of the details of the interaction.

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Relativistic view on the nuclear effects in the deep inelastic scattering on deuteron

We analyze nuclear effects in the deep inelastic scattering on deuteron in the framework of the covariant approach. It is shown that this approach gives us the way to investigate the role of relativistic effects in the deep inelastic scattering (DIS) on deuteron, such as the relativistic kinematics and the off-mass-shell behavior of the Compton amplitude of nucleon in the consistent manner. We have obtained that taking into account of the nucleon amplitude off-mass-shell behavior gives us an analog of the interaction corrections in nonrelativistic models.

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Magnetic moment of the deuteron as probe of relativistic corrections

The calculation of the magnetic moment of the deuteron in the framework of the Bethe--Salpeter approach is performed. The relativistic corrections are calculated analytically and estimated numerically. It is shown that the main contributions are due to partial waves with positive energies and $P$--waves. A comparison with the non-relativistic schemes of calculations including mesonic exchange currents is made.

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Hadron and Quark Form Factors in the Relativistic Harmonic Oscillator Model

Nucleon, pion and quark form factors are studied within the relativistic harmonic oscillator model including the quark spin. It is shown that the nucleon charge, magnetic and axial form factors and the pion charge form factor can be explained with one oscillator parameter if one accounts for the scaling rule and the size of the constituent quarks.

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