# Quasiparticle time blocking approximation in coordinate space as a model for the damping of the giant dipole resonance

## Abstract

The quasiparticle time blocking approximation (QTBA) is presented as a model for the description of natural-parity excitations in open-shell nuclei. Most attention is paid to the question of the damping of the giant dipole resonance. Within the model pairing correlations, two-quasiparticle (2q), and 2qxphonon configurations are included. Thus the QTBA is an extension of the quasiparticle random phase approximation to include quasiparticle-phonon coupling. Calculational formulas are presented for the case of neutral natural-parity excitations in spherical nuclei. The main equations are written in the coordinate representation that allows to take into account single-particle continuum completely. The QTBA is applied to describe E1 photoabsorption cross sections in nuclei {sup 116,120,124}Sn. It has been obtained that the 2q(multiply-in-circle sign)phonon configurations provide noticeable fragmentation of the giant dipole resonance resulting in the appearance of a significant spreading width. The results are compared with available experimental data.

- Authors:

- Institute of Physics and Power Engineering, RU-249033 Obninsk (Russian Federation)
- (Germany)
- Nuclear Physics Department, V. A. Fock Institute of Physics, St. Petersburg State University, RU-198504 St. Petersburg (Russian Federation)

- Publication Date:

- OSTI Identifier:
- 20995280

- Resource Type:
- Journal Article

- Resource Relation:
- Journal Name: Physical Review. C, Nuclear Physics; Journal Volume: 75; Journal Issue: 5; Other Information: DOI: 10.1103/PhysRevC.75.054318; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 73 NUCLEAR PHYSICS AND RADIATION PHYSICS; CHANNELING; CROSS SECTIONS; DIPOLES; EXCITATION; PARITY; PHONONS; RANDOM PHASE APPROXIMATION; RESONANCE; SPHERICAL CONFIGURATION; TIN 116; TIN 120; TIN 124

### Citation Formats

```
Litvinova, E. V., Physik-Department der Technischen Universitaet Muenchen, D-85748 Garching, and Tselyaev, V. I..
```*Quasiparticle time blocking approximation in coordinate space as a model for the damping of the giant dipole resonance*. United States: N. p., 2007.
Web. doi:10.1103/PHYSREVC.75.054318.

```
Litvinova, E. V., Physik-Department der Technischen Universitaet Muenchen, D-85748 Garching, & Tselyaev, V. I..
```*Quasiparticle time blocking approximation in coordinate space as a model for the damping of the giant dipole resonance*. United States. doi:10.1103/PHYSREVC.75.054318.

```
Litvinova, E. V., Physik-Department der Technischen Universitaet Muenchen, D-85748 Garching, and Tselyaev, V. I.. Tue .
"Quasiparticle time blocking approximation in coordinate space as a model for the damping of the giant dipole resonance". United States.
doi:10.1103/PHYSREVC.75.054318.
```

```
@article{osti_20995280,
```

title = {Quasiparticle time blocking approximation in coordinate space as a model for the damping of the giant dipole resonance},

author = {Litvinova, E. V. and Physik-Department der Technischen Universitaet Muenchen, D-85748 Garching and Tselyaev, V. I.},

abstractNote = {The quasiparticle time blocking approximation (QTBA) is presented as a model for the description of natural-parity excitations in open-shell nuclei. Most attention is paid to the question of the damping of the giant dipole resonance. Within the model pairing correlations, two-quasiparticle (2q), and 2qxphonon configurations are included. Thus the QTBA is an extension of the quasiparticle random phase approximation to include quasiparticle-phonon coupling. Calculational formulas are presented for the case of neutral natural-parity excitations in spherical nuclei. The main equations are written in the coordinate representation that allows to take into account single-particle continuum completely. The QTBA is applied to describe E1 photoabsorption cross sections in nuclei {sup 116,120,124}Sn. It has been obtained that the 2q(multiply-in-circle sign)phonon configurations provide noticeable fragmentation of the giant dipole resonance resulting in the appearance of a significant spreading width. The results are compared with available experimental data.},

doi = {10.1103/PHYSREVC.75.054318},

journal = {Physical Review. C, Nuclear Physics},

number = 5,

volume = 75,

place = {United States},

year = {Tue May 15 00:00:00 EDT 2007},

month = {Tue May 15 00:00:00 EDT 2007}

}