A. I. Mazur

Realistic nuclear Hamiltonian: Ab exitu approach

Fully-microscopic No-core Shell Model (NCSM) calculations of all stable s and p shell nuclei are used to determine realistic NN interaction JISP16 describing not only the two-nucleon data but the binding energies and spectra of nuclei with A {le} 16 as well. The JISP16 interaction, providing rapid convergence of the NCSM calculations, is obtained in an ab exitu approach by phase-equivalent transformations of the JISP6 NN interaction.

Novel NN interaction and the spectroscopy of light nuclei

Abstract Nucleon–nucleon ( NN ) phase shifts and the spectroscopy of A ⩽ 6 nuclei are successfully described by an inverse scattering potential that is separable with oscillator form factors.

Description of resonant states in the shell model

A technique for describing scattering states within the nuclear shell model is proposed. This technique is applied to scattering of nucleons by particles based on ab initio No-Core Shell Model calculations of 5He and 5Li nuclei with JISP16 NN interaction.

Oscillator basis, scattering and nuclear structure

We note that a Lanczos algorithm can be used to generate a harmonic oscillator basis. We use it to formulate quantum scattering theory utilizing an expansion of scattering wave functions in series of oscillator functions. The continuum spectrum solutions of the Schr?dinger equation are found by means of Lanczos iterations. This formalism provides a possibility to extend a nuclear shell model, in particular, an ab initio no-core shell model, on a scattering domain.

Light nuclei in ab initio approach with realistic inverse scattering NN-interaction

We discuss the studies of light nuclei in ab initio No-core Full Configuration approach based on extrapolations to the infinite model space of large-scale No-core Shell Model calculations on supercomputers. The convergence at the end of p shell and beginning of the sd shell can be achieved if only reasonable soft enough NN interactions are used. In particular, good predictions are obtained with a realistic JISP16 NN interaction obtained in J-matrix inverse scattering approach and fitted to reproduce light nuclei observables without three-nucleon forces. We discuss the current status of this NN interaction and its recent development.

Phase-equivalent transformation which does not affect bound state properties and its manifestation in many-body systems

We propose a phase-equivalent transformation of NN interaction of a new type, the DET-PET transformation, which does not affect the wave function of the bound system (deuteron). The DET-PET properties and its manifestation in many-body systems are studied. In particular, we investigate the correlation of the 3H and 4He binding energies (the Tjon line) in calculations with NN potentials obtained by means of DET-PET from the JISP16 NN interaction.

Further development of realistic JISP16 NN interaction

An improvement of a realistic nonlocal JISP16 NN interaction that provides a more accurate description of the binding energies and spectra of light nuclei without using three-nucleon forces, is considered.

Resonant parameters of 5He and 5Li states and nucleon-α scattering

A new method of analysis of resonant parameters in the framework of the J-matrix inverse scattering formalism is proposed. The method is applied to analysis of Nα scattering in various partial waves. The obtained 1/2− and 3/2− resonance energies and widths in 5He and 5Li nuclei are in good agreement with the results of other approaches. The eigenenergies entering the J-matrix phase shift parameterization are shown to correlate well with the respective results of no-core shell model calculations, in particular, in the case of non-resonant s-wave scattering.

Spectroscopy of light nuclei with realistic NN interaction JISP

Recent results of our systematic ab initio studies of the spectroscopy of s- and p-shell nuclei in fully microscopic large-scale (up to a few hundred million basis functions) no-core shell-model calculations are presented. A new high-quality realistic nonlocal NN interaction JISP is used. This interaction is obtained in the J-matrix inverse-scattering approach (JISP stands for the J-matrix inverse-scattering potential) and is of the form of a small-rank matrix in the oscillator basis in each of the NN partial waves, providing a very fast convergence in shell-model studies. The current purely two-body JISP model of the nucleon-nucleon interaction JISP16 provides not only an excellent description of two-nucleon data (deuteron properties and np scattering) with χ2/datum = 1.05 but also a better description of a wide range of observables (binding energies, spectra, rms radii, quadrupole moments, electromagnetic-transition probabilities, etc.) in all s-and p-shell nuclei than the best modern interaction models combining realistic nucleon-nucleon and three-nucleon interactions.

Charge-dependent NN interaction in the J-matrix inverse scattering approach

A method for constructing interaction within the J-matrix inverse scattering approach in the case of charged particles is proposed. A charge-dependent nonlocal nucleon-nucleon interaction (CD JISP) has been constructed, which is a generalization of the JISP16 interaction. Interaction in pp, nn, and np partial waves is presented by small matrices in the oscillator basis with ħω = 40 MeV; therefore, it can be directly used in many-body calculations within the shell model and in the resonating group model. The CD JISP interaction reproduces the np-and pp-scattering data and deuteron observables with high accuracy.