# Large-basis ab initio no-core shell model and its application to {sup 12}C

## Abstract

We present the framework for the ab initio no-core nuclear shell model and apply it to obtain properties of {sup 12}C. We derive two-body effective interactions microscopically for specific model spaces from the realistic CD-Bonn and the Argonne V8' nucleon-nucleon (NN) potentials. We then evaluate binding energies, excitation spectra, radii, and electromagnetic transitions in the 0{Dirac_h}{Omega}, 2{Dirac_h}{Omega}, and 4{Dirac_h}{Omega} model spaces for the positive-parity states and the 1{Dirac_h}{Omega}, 3{Dirac_h}{Omega}, and 5{Dirac_h}{Omega} model spaces for the negative-parity states. Dependence on the model-space size, on the harmonic-oscillator frequency, and on the type of the NN potential, used for the effective interaction derivation, are studied. In addition, electromagnetic and weak neutral elastic charge form factors are calculated in the impulse approximation. Sensitivity of the form-factor ratios to the strangeness one-body form-factor parameters and to the influence of isospin-symmetry violation is evaluated and discussed. Agreement between theory and experiment is favorable for many observables, while others require yet larger model spaces and/or three-body forces. The limitations of the present results are easily understood by virtue of the trends established and previous phenomenological results.

- Authors:

- Publication Date:

- Sponsoring Org.:
- (US)

- OSTI Identifier:
- 40206081

- Resource Type:
- Journal Article

- Journal Name:
- Physical Review C

- Additional Journal Information:
- Journal Volume: 62; Journal Issue: 5; Other Information: DOI: 10.1103/PRC.62.054311; Othernumber: PRVCAN000062000005054311000001; 063011PRC; PBD: Nov 2000; Journal ID: ISSN 0556-2813

- Publisher:
- The American Physical Society

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 73 NUCLEAR PHYSICS AND RADIATION PHYSICS; ENERGY-LEVEL TRANSITIONS; EXCITATION; FORM FACTORS; IMPULSE APPROXIMATION; SENSITIVITY; SHELL MODELS; SPECTRA; STRANGENESS

### Citation Formats

```
Navratil, P., Vary, J. P., and Barrett, B. R.
```*Large-basis ab initio no-core shell model and its application to {sup 12}C*. United States: N. p., 2000.
Web. doi:10.1103/PRC.62.054311.

```
Navratil, P., Vary, J. P., & Barrett, B. R.
```*Large-basis ab initio no-core shell model and its application to {sup 12}C*. United States. doi:10.1103/PRC.62.054311.

```
Navratil, P., Vary, J. P., and Barrett, B. R. Wed .
"Large-basis ab initio no-core shell model and its application to {sup 12}C". United States. doi:10.1103/PRC.62.054311.
```

```
@article{osti_40206081,
```

title = {Large-basis ab initio no-core shell model and its application to {sup 12}C},

author = {Navratil, P. and Vary, J. P. and Barrett, B. R.},

abstractNote = {We present the framework for the ab initio no-core nuclear shell model and apply it to obtain properties of {sup 12}C. We derive two-body effective interactions microscopically for specific model spaces from the realistic CD-Bonn and the Argonne V8' nucleon-nucleon (NN) potentials. We then evaluate binding energies, excitation spectra, radii, and electromagnetic transitions in the 0{Dirac_h}{Omega}, 2{Dirac_h}{Omega}, and 4{Dirac_h}{Omega} model spaces for the positive-parity states and the 1{Dirac_h}{Omega}, 3{Dirac_h}{Omega}, and 5{Dirac_h}{Omega} model spaces for the negative-parity states. Dependence on the model-space size, on the harmonic-oscillator frequency, and on the type of the NN potential, used for the effective interaction derivation, are studied. In addition, electromagnetic and weak neutral elastic charge form factors are calculated in the impulse approximation. Sensitivity of the form-factor ratios to the strangeness one-body form-factor parameters and to the influence of isospin-symmetry violation is evaluated and discussed. Agreement between theory and experiment is favorable for many observables, while others require yet larger model spaces and/or three-body forces. The limitations of the present results are easily understood by virtue of the trends established and previous phenomenological results.},

doi = {10.1103/PRC.62.054311},

journal = {Physical Review C},

issn = {0556-2813},

number = 5,

volume = 62,

place = {United States},

year = {2000},

month = {11}

}