Tensor target spin asymmetries [Formula: see text] ([Formula: see text]=0,1,2) in the reaction [Formula: see text] are studied for photon energies from [Formula: see text]-threshold up to 1.5[Formula: see text]GeV with inclusion of... more
Tensor target spin asymmetries [Formula: see text] ([Formula: see text]=0,1,2) in the reaction [Formula: see text] are studied for photon energies from [Formula: see text]-threshold up to 1.5[Formula: see text]GeV with inclusion of rescattering effects. It is shown that the influence of rescattering effects on the tensor target spin asymmetries is sizable in the energy region near [Formula: see text]-threshold. At higher energies, much smaller influence of rescattering effects is seen. The sensitivity of the obtained results to the elementary pion photoproduction operator is investigated and a considerable dependence is found, in particular at forward pion angles. In addition, a comparison with results of other theoretical models is also given. The extracted spin asymmetries are compared with available experimental data and a qualitative agreement is obtained. The predictions presented here may be useful to interpret the recent measurements from the VEPP-3 electron storage ring.
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We study the properties of symmetric nuclear matter and pure neutron matter at zero temperature within the framework of the Brueckner theory using tabulated values of effective masses and depth of the single-particle energies. These... more
We study the properties of symmetric nuclear matter and pure neutron matter at zero temperature within the framework of the Brueckner theory using tabulated values of effective masses and depth of the single-particle energies. These tabulated values are chosen according to the work of Hassaneen et al, 2011. The Brueckner–Hartree–Fock approximation plus a density-dependent contact term as a three-body force are used to achieve the empirical saturation property of symmetric nuclear matter. The three-body force provides a strong enhancement of pressure and incompressibility in good agreement with relativistic approaches. Realistic nucleon-nucleon interactions which reproduce the nucleon-nucleon phase shifts are used in the present calculations. Good agreement is obtained in comparison with the experimental data.
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Results of cold and hot asymmetric nuclear matter and pure neutron matter calculations are presented. The (BHF) approximation + two body density dependent Skyrme potential which is equivalent to three - body interaction are used. Various... more
Results of cold and hot asymmetric nuclear matter and pure neutron matter calculations are presented. The (BHF) approximation + two body density dependent Skyrme potential which is equivalent to three - body interaction are used. Various modern nucleon-nucleon (NN) potentials are used as follows: CD-Bonn potential, Nijm1 potential, Reid 93 potential and Argonne V18 potential are used in the framework of (BHFA). The bulk properties of asymmetric nuclear matter are computed such as the EOS at (T = 0), pressure at (T = 0, 5 and 10 MeV), single particle potential, entropy at (T = 5 and 10 MeV), free energy at (T = 5 and 10 MeV), nuclear matter incompressibility and the symmetry energy. Also the bulk properties of pure neutron matter are computed such as the EOS at (T = 0), pressure at (T = 0, 3 and 6 MeV), single particle potential, entropy at (T = 3 and 6 MeV), free energy at (T = 3 and 6 MeV). The results are compared with B. Freidman and V. R. PandhariPand [45]. By this method good a...
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Abstract.A self-consistent Green’s Function approach is used to study the influence of short-range correlations beyond the mean-field approach of nuclear matter. The ladder equation, including both particle-particle and hole-hole... more
Abstract.A self-consistent Green’s Function approach is used to study the influence of short-range correlations beyond the mean-field approach of nuclear matter. The ladder equation, including both particle-particle and hole-hole propagation, is solved in nuclear matter for a realistic interaction derived from the CD-Bonn potential. The hole-hole interaction is used to calculate the spectral functions that describe the distribution of holes below Fermi level. The nucleon spectral functions are calculated from the momentum- and energy-dependent self-energy. For comparison, the calculations are investigated by including nuclear three-body force. These spectral functions directly reflect the effects of the nucleon-nucleon correlations and can be explored by the analysis of nucleon knock-out experiments like $ ({\rm e, e' p})$(e,ep).
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The properties of asymmetric nuclear matter have been investigated in the framework of the self-consistent Green function approach at zero temperature. Results of the total energy per nucleon as a function of the density and asymmetry... more
The properties of asymmetric nuclear matter have been investigated in the framework of the self-consistent Green function approach at zero temperature. Results of the total energy per nucleon as a function of the density and asymmetry parameter are presented for two ...
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Symmetric nuclear matter is studied within the Brueckner-Hartree-Fock (BHF) approach and is extending to the self-consistent Green’s function (SCGF) approach. Both approximations are based on realistic nucleon-nucleon interaction; that... more
Symmetric nuclear matter is studied within the Brueckner-Hartree-Fock (BHF) approach and is extending to the self-consistent Green’s function (SCGF) approach. Both approximations are based on realistic nucleon-nucleon interaction; that is, CD-Bonn potential is chosen. The single-particle energy and the equation of state (EOS) are studied. The Fermi energy at the saturation point fulfills the Hugenholtz-Van Hove theorem. In comparison to the BHF approach, the binding energy is reduced and the EOS is stiffer. Both the SCGF and BHF approaches do not reproduce the correct saturation point. A simple contact interaction should be added to SCGF and BHF approaches to reproduce the empirical saturation point.
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The properties of nuclear matter at zero and finite temperatures in the frame of the Brueckner theory realistic nucleon-nucleon potentials are studied. Comparison with other calculations is made. In addition we present results for the... more
The properties of nuclear matter at zero and finite temperatures in the frame of the Brueckner theory realistic nucleon-nucleon potentials are studied. Comparison with other calculations is made. In addition we present results for the symmetry energy obtained with different potentials, which is of great importance in astrophysical calculation. Properties of asymmetric nuclear matter are derived from various many-body approaches. This includes phenomenological ones like the Skyrme Hartree-Fock and relativistic mean field approaches, which are adjusted to fit properties of nuclei, as well as more microscopic attempts like the BHF approximation, a Self-Consistent Greens Function (SCGF) method and the so-called Vlowk approach, which are based on realistic nucleon-nucleon interactions which reproduce the nucleon-nucleon phase shifts. These microscopic approaches are supplemented by a density-dependent contact interaction to achieve the empirical saturation property of symmetric nuclear m...
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Studies on the structure of nuclear systems are performed, ~which are based on realistic nucleon-nucleon interactions. Such realistic interactions induce two-body correlations in the nuclear many-body wave function. In particular one... more
Studies on the structure of nuclear systems are performed, ~which are based on realistic nucleon-nucleon interactions. Such realistic interactions induce two-body correlations in the nuclear many-body wave function. In particular one finds deviations of the single-particle Green's function from the mean field prediction of a Hartree-Fock theory. Such modifications give rise to a modification in the response function of the nuclear system. This response function characterizes the excitation modes of the nuclear system. It is also the most relevant ingredient for the study of the propagator of a meson in the nuclear medium. This meson propagators, on the other hand, ~are very important to study modifications of the nucleon-nucleon force in the nuclear medium and thereby influence the self-consistent evaluation of the single-particle Green's function. The nuclear spectral function at high missing energies and momenta has been determined from a self-consistent calculation of the...
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ABSTRACT We investigated the argument of recent publications that the good description of the nucleon-nucleon NN interaction at short distances by quark models is at present only qualitative. The quark model is simulated at short... more
ABSTRACT We investigated the argument of recent publications that the good description of the nucleon-nucleon NN interaction at short distances by quark models is at present only qualitative. The quark model is simulated at short distances by a repulsive short range nonlocality. For larger radii, the one pion exchange potential OPEP is used. We found that the quark model alone at the core region can only reproduce the deuteron binding energy, but ¯tting other NN properties needs high local repulsion.
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Abstract The one-body potentials for protons and neutrons are obtained from the self-consistent Green-function calculations of asymmetric nuclear matter, in particular their dependence on the degree of proton/neutron asymmetry. Results of... more
Abstract The one-body potentials for protons and neutrons are obtained from the self-consistent Green-function calculations of asymmetric nuclear matter, in particular their dependence on the degree of proton/neutron asymmetry. Results of the binding energy ...
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In this paper we have reported the study of symmetry energy within the self-consistent Green-function approach. For the sake of comparison, the same calculations are performed using Brueckner-Hartree-Fock approximation. The symmetry... more
In this paper we have reported the study of symmetry energy within the self-consistent Green-function approach. For the sake of comparison, the same calculations are performed using Brueckner-Hartree-Fock approximation. The symmetry energy is calculated for different densities and discussed in comparison with other predictions. The self-consistent Green's function leads to slightly larger energies as compared to the Brueckner-Hartree-Fock approach. This
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The binding energy of nuclear matter at zero temperature in the Brueckner–Hartree–Fock approximation with modern nucleon–nucleon potentials is studied. Both the standard and continuous choices of single particle energies are used. These... more
The binding energy of nuclear matter at zero temperature in the Brueckner–Hartree–Fock approximation with modern nucleon–nucleon potentials is studied. Both the standard and continuous choices of single particle energies are used. These modern nucleon–nucleon ...