Narrow Results

We report our research work on the equation of state (EOS) and single-particle (s.p.) properties of neutron-rich nuclear matter within the framework of the Brueckner–Bethe–Goldstone approach extended to include a microscopic three-body force (TBF). We show that inclusion of the TBF provide a largely improvement of the predicted nuclear matter saturation properties and leads to a strongly stiffening of the density dependence of symmetry energy at high densities. The neutron effective mass turns out to be greater than the proton one in neutron-rich nuclear matter in both cases of including and not including the TBF. The TBF induces a strongly repulsive rearrangement contribution to nucleon s.p. potential at high densities and large momenta. The TBF rearrangement contribution reduces considerably the attraction of the neutron and proton s.p. potentials and enhances strongly their momentum-dependence at high densities and high momenta. The TBF effect on nucleon superfluidity in neutron star matter has also been discussed.

Different theoretical models for two- and three-body electromagnetic currents are constructed using meson-exchange mechanisms and minimal substitution in the momentum dependence of two- and three-nucleon interactions. We review the use of effective field theory (EFT) to compute electromagnetic reactions in three-nucleon systems at very low energies. We first explain how EFT theory can be extended to incorporate the photon into the three-nucleon systems when also a three-nucleon force is acting. We also explain the predictions of the resulting EFT for neutron–deuteron radiative capture process at very low energies. In this work, a number of low-energy photonuclear observables, including neutron–deuteron radiative capture reactions and triton photodisintegration, are calculated in order to make a comparative study of the pion-less EFT results with the models based on the realistic Argonne v18(AV18) two-nucleon and Urbana IX or Tucson–Melbourne three-nucleon interactions. The calculated cross-section of neutron–deuteron radiative capture and photon polarization parameter of ³H are in satisfactory agreement with the available experimental data.

The photodisintegration cross section of ⁴He is calculated using the realistic nucleon-nucleon potential Argonne V18 (AV18) and the three-body force Urbana IX (UIX). Final State interaction is taken into account via the Lorentz Integral Transform method. A comparison with other potential models and with the available experimental data is discussed.

We investigate the equation of state (EOS) and single particle properties of isospin asymmetric nuclear matter by using the Brueckner theory. We have concentrated on the effect of microscopic three-body forces and studied especially the isospin dependence of the EOS and the properties of asymmetric nuclear matter.

We investigate the equation of state (EOS) and single-particle (s.p.) properties of asymmetric nuclear matter (including the neutron and proton s.p. potentials and effective masses, symmetry potential, neutron/proton effective mass splitting) by using the Brueckner approach extended to include microscopic three-body forces. We have concentrated on the isospin-dependence of the properties of asymmetric nuclear matter and the TBF effects. We have discussed especially the TBF-induced rearrangement effect on the s.p. properties and their isospin behavior in neutron-rich nuclear medium.

The present status of the microscopic theory for complex optical potentials of nucleus-nucleus systems is reviewed in the present talk, including the brief history and the latest achievement in the theoretical analysis of elastic scattering of light heavy-ion systems on the basis of double-folding model with the use of the CEG07 G-matrix interaction recently proposed by the present authors, with a special emphasis upon the role of the three-body force.