Mechanism of Proton-Induced Reactions on Targets ^16O, ^27Al, ^56Fe, ^112Cd, ^184W and ^208Pb At Ep = 800 MeV

We investigate the 800 MeV proton-induced spallation reactions on various targets by the improved quantum molecular dynamics （ImQMD05） model incorporated with a statistical decay model （SDM）. The influence of the nucleon-nucleon effective interaction on proton induced spallation reactions is studied by using different Skyrme interactions. It is found that the low energy part of the neutron double differential cross sections （DDCS）, which is mainly contributed from the decay of the excited residue, is influenced by the effective nucleon-nucleon interaction strongly., while the high energy part of neutron DDCS is influenced weakly. Among the Skyrme interactions used in the calculations, the calculation results with SkP give the best agreement with the experimental data.     

Influence of two different representations of the G-matrix to the in-medium nucleon-nucleon cross sections

We calculate the in-medium nucleon-nucleon scattering cross sections from the G-matrix using the Dirac-Brueckner-Hartree-Fock (DBHF) approach. And we investigate the influence of the different representations of the $G$-matrix to the cross sections, the difference of which is mainly from the different effective masses.     

A Separable Pairing Force in Nuclear Matter

The method introduced by Duguet is adopted to derive a separable form of the pairing interaction in the ^1So channel from a bare or an effective nucleon-nucleon （NN） interaction in nuclear matter. With this approach the separable pairing interaction reproduces the pairing properties provided by its corresponding NN interaction. In this work, separable forms of pairing interactions in the ^1So channel for the bare NN interaction, Bonn potential and the Gogny effective interaction are obtained. It is found that the separable force of the Gogny effective interaction in the 1So channel has a clear link with the bare NN interaction. With such a simple separable form pairing properties provided by the Gogny force in nuclear matter can be reproduced.     

Restoration of rotational symmetry in deformed relativistic mean-field theory

We report on a very recently developed three-dimensional angular momentum projected relativistic mean-field theory with point-coupling interaction (3DAMP+RMF-PC). Using this approach the same effective nucleon-nucleon interaction is adopted to describe both the single-particle and collective motions in nuclei. Collective states with good quantum angular momentum are built projecting out the intrinsic deformed meanfield states. Results for 24Mg are shown as an illustrative application.     

Decomposition of the equation of state of asymmetric nuclear matter into different spin-isospin channels

We investigate the equation of state of asymmetric nuclear matter and its isospin dependence in various spin-isospin ST channels within the framework of the Brueckner-Hartree-Fock approach extended to include a microscopic three-body force（TBF） . It is shown that the potential energy per nucleon in the isospinsinglet T = 0 channel is mainly determined by the contribution from the tensor SD coupled channel. At high densities,the TBF effect on the isospin-triplet T = 1 channel contribution turns out to be much larger than that on the T =0 channel contribution. At low densities around and below the normal nuclear matter density,the isospin dependence is found to come essentially from the isospin-singlet SD channel and the isospin-triplet T = 1 component is almost independent of isospin asymmetry. As the density increases,the T = 1 channel contribution becomes sensitive to the isospin asymmetry and at high enough densities its isospin dependence may even become more pronounced than that of the T = 0 contribution. The present results may provide some microscopic constraints for improving effective nucleon-nucleon interactions in a nuclear medium and for constructing new functionals of effective nucleon-nucleon interaction based on microscopic many-body theories.     

Restoration of rotational symmetry in deformed relativistic mean-field theory

We report on a very recently developed three-dimensional angular momentum projected relativistic mean-field theory with point-coupling interaction (3DAMP+RMF-PC). Using this approach the same effective nucleon-nucleon interaction is adopted to describe both the single-particle and collective motions in nuclei. Collective states with good quantum angular momentum are built projecting out the intrinsic deformed mean-field states. Results for ²⁴Mg are shown as an illustrative application.     

Shell Model Description of Neutron-Deficient Sn Isotopes

The shell model calculations in the sdgh major shell for the neutron-deficient ^106,107,108,109Sn isotopes have been carried out by using CD-Bonn and Nijmegenl two-body effective nucleon-nucleon interactions. The singleshell states and the corresponding matrix elements needed for describing Sn isotopes are reconstructed to calculate the coefficient of fractional parantage by reducing the calculation requirements. This reconstruction allows us to do the shell model calculations of the neutron deficient Sn isotopes in very reasonable time. The results are compared to the recent high-resolution experimental data and found to be in good agreement with experiments.     

Medium Suppression of In medium Nucleon-Nucleon Cross Sections Predicted with Various Microscopic Calculations

The nucleon-nucleon cross sections in the dense nuclear matter are microscopically calculated by using Dirac- Brueckner-Hartree-Fock （DBHF） approximation with different covariant representations of the T-matrix, i.e., complete pseudo-vector （CPV）, pseudoscalar （PS） and pseudo-vector （PV） choices. Special attention is paid to the discrepancies among the cross sections calculated with these different T-matrix project choices. The results show that the medium suppression of the cross section given by DBHF in the CPV choice is not only smaller than those obtained in both PS and PV choices, but also smaller than the predictions with a nonrelativistic Brueckner-Hartree-Fock （BHF） method including three body force （3BF）. The further analysis reveals that the influence of the different choices on the cross section in the DBHF approximation is mainly determined by the state of smaller total angular momentum due to the medium effect being strongly suppressed in the higher angular momentum.     

The influence of Isospin Dependence of In-Medium NN Cross Sections on the Ratio of Emitted Neutrons to Protons in HICs

The influence of isospin dependence of in-medium nucleon-nucleon cross sections on the nip ratios for emitted nucleons in reactions 96Zr-j-96Zr and 96Ru-j-96RH at Eb z 400 AMeV is investigated by means of an improved quantum molecular dynamics model. Our results show that the high energy part of the spectra of the n//p ratios for emitted nucleons is sensitive to the isospin dependence of in-medium nucleon-nucleon cross sections for neutron-rich reaction systems. Therefore, we propose that the nip ratio of emitted high energy nucleons in a very neutron-rich reaction system at several hundreds of AMeV can be taken as sensitive observables to constrain the isospindependence of in-medium nucleon-nucleon cross sections.     

Calculation of Radii and Density of ^7-19B Isotopes Using Effective Skyrme Force

Abstract In this study, the proton and neutron densities, charge densities, rms nuclear charge radii, rms nuclear mass radii, rms nuclear proton, neutron radii, and neutron skin thickness are calculated by using Harfree-Fock method with an effective nucleon-nucleon Skyrme interactions with SⅠ, SⅡ, SⅣ, T3, SKM, and SKM^＊ parameters. These nuclear properties for the neutron-rich isotopes of B （Boron） are presented. The calculated results are compared with the experimental and theoretical results of other researchers.     

Calculation of α decay half-lives for superheavy elements using the double folding model＊

α decay half-lives of some new synthesized superheavy elements, possibly synthesized superheavy elements and decay products are calculated theoretically within the WKB approximation by using microscopic α-nucleus interaction potentials. These nuclear potentials between the α particle and daughter nuclei are obtained by using the double folding integral of the matter density distribution of the α particle and daughter nuclei with a density-dependent effective nucleon-nucleon interaction, in which the zero-range exchange term is supplemented. The calculated α decay half-lives are compared with those of the different models and experimental data. It is shown that the present calculation successfully provides the half-lives of the observed decays for some new superheavy elements and therefore gives reliable predictions for α decay of possibly synthesized superheavy elements in future experiments.     

The Photon Polarization Parameter of 2H（n, γ）3H reaction with Inclusion of the Electric Quadrupole Contribution

We use effective field theory （EFT） for the calculation of neutron-deuteron radiative capture at very low energies. We present here the use of EFT to calculate a low-energy photo-nuclear observable in three-body systems, the photon polarization parameter and and fore-aft asymmetry at thermal neutron energies up to next-to-next to leading order （N2 LO）, with inclasion of the electric quadrupole contribution. The photon polarization parameter in total is found to be Rc = -0.421±0.003 and is in good agreement with the other modern theoretical calculations based on modern nucleon-nucleon potentials. In comparison with our previous work, a satisfactory agreement with the available experimental data is found by inclusion of the electric quadrupole contribution.     

Medium Influence of the Nucleon—Nucleon Cross Section on the Fragmentation

Based on an isospin-dependent quantum molecular dynamics model we studied the influence of a medium correction of an isospin-dependent nucleon-nucleon cross section on the fragmentation at the intermediate energy heavy-ion collisions. We found that the medium correction from an isospin-dependent nucleon-nucleon cross section, at the same time, the momentum-dependent interaction also produces an important role for enhancing the influence of the medium correction on the isospin effect of two-body collisions in the fragmentation process.     

Nucleon-Nucleon Interaction and the Mixing of Scalar Meson

Whether the mixing of scalar meson exists or not is an interesting question. We consider the mixing of scalar meson and further study the nucleon-nucleon interaction in the chiral SU（3） quark model by solving the resonating group method equation. The results are analyzed and compared with no mixing, ideal mixing and general mixing. It seems that the nucleon-nucleon interaction and binding energy of deuteron can be reasonably described with the different mixing of scalar meson.     

Pade Expansion and Nucleon-Nucleon Scattering in Coupled Channels

We extend our Pade-aided analysis of the nonperturbative renormalization of nucleon-nucleon scattering to the case of coupled channels.     

Calculation of decay half-lives for superheavy elements using the double folding model

α decay half-lives of some new synthesized superheavy elements, possibly synthesized superheavy elements and decay products are calculated theoretically within the WKB approximation by using microscopic m-nucleus interaction potentials. These nuclear potentials between the α particle and daughter nuclei are obtained by using the double folding integral of the matter density distribution of the α particle and daughter nuclei with a density-dependent effective nucleon-nucleon interaction, in which the zero-range exchange term is supplemented. The calculated α decay half-lives are compared with those of the different models and experimental data. It is shown that the present calculation successfully provides the half-lives of the observed αdecays for some new superheavy elements and therefore gives reliable predictions for α decay of possibly synthesized superheavy elements in future experiments.     

Towards Lambda-nucleon coupling constants in relativistic mean field theory

New parameter sets for Λ-nucleon coupling in relativistic mean field theory are proposed based on nucleon-nucleon effective interaction PK1. Hypernuclear properties are described well through a systematical study. Effects of hyperon tensor coupling term on spin-orbit splitting are also investigated self-consistently.