Searching for single-particle resonances with the Green’s function method

Single-particle resonances in the continuum are crucial for studies of exotic nuclei.In this study,the Green’s function approach is employed to search for single-particle resonances based on the relativistic-mean-field model.Taking^(120)Sn as an example,we identify singleparticle resonances and determine the energies and widths directly by probing the extrema of the Green’s functions.In contrast to the results found by exploring for the extremum of the density of states proposed in our recent study[Chin.Phys.C,44:084105(2020)],which has proven to be very successful,the same resonances as well as very close energies and widths are obtained.By comparing the Green’s functions plotted in different coordinate space sizes,we also found that the results very slightly depend on the space size.These findings demonstrate that the approach by exploring for the extremum of the Green’s function is also very reliable and effective for identifying resonant states,regardless of whether they are wide or narrow.

Deformations and B（E2） Values of Ne and Mg Nuclei around N = 20

The ground-state deformations and B（E2） values of Ne and Mg nuclei around N = 20 are studied within the framework of the macroscopic-microscopic （MM） model with isospin-dependent Nilsson potential. The calculated results are compared with those obtained from standard Nilsson parameters and with experimental ones. It is found that the calculations with new Nilsson parameters well reproduce the experimental large deformations and B（E2） values for Ne and Mg nuclei around N = 20. The N = 20 shell closure of Ne and Mg isotopes disappears in the MM model and this agrees with experimental data.

Cross Sections of Elastic Electron and Positron Scattering from Proton-Rich Nuclei

We investigate the cross sections of the elastic electron or positron scat tering from 208 Pb, ^12C ^12,16O and ^28,32S by the relativistic partial-wave expansion method using the static charge density distribution from the self-consistent relativistic mean fiel model and also calculate the charge form factor for ^12＇16O and ^28,32S. The numerical results are compared with the available data. Calculations indicate that the extended charge density distributions of ^12O and ^28S have observable effects on the cross sections of the electron or positron scattering as well as the charge form factors.

Radius studies of ^8Li and ^8B using the optical-limit Glauber model in conjunction with relativistic mean-field theory

We study the reaction cross sections （σR） and root-mean-square （RMS） radii of ^8Li and ^8B, the halo-like nuclei, with stable target ^12C, ^27Al and ^9Be within the standard optical-limit Glauber model, using densities obtained from relativistic mean-field （RMF） formalisms and other types of distributions. It is found that the experimental σR can be reproduced well at high energy. The RMS radius and Ar extracted by RMF- theory and harmonic oscillator distribution are compared. larger than those of SLi. In addition, we analyze in detail the We find that the RMS radius and Ar of SB are relationship between σR and density distribution.

Single-particle resonant states with Green’s function method

This study employs the relativistic mean field theory with the Green's function method to study the single-particle resonant states.In contrast to our previous work[Phys.Rev.C,90:054321(2014)],the resonant states are identified by searching for the poles of Green's function or the extremes of the density of states.This new approach is highly effective for all kinds of resonant states,no matter whether they are broad or narrow.The dependence on the space size for the resonant energies,widths,and the density distributions in the coordinate space has been checked and was found to be very stable.Taking ^120Sn as an example,four new broad resonant states 2g7/2,2g9/2,2h11/2,and 1j13/2 were observed,and the accuracy for the width of the very narrow resonant state 1h9/2 was highly improved to 1×10^−8 MeV.Further,our results are very close to those obtained using the complex momentum representation method and the complex scaling method.