Effect of Core Excitations on 29Si and on the Giant Dipole Resonance in 28Si

1973 ◽  
Vol 51 (9) ◽  
pp. 988-992 ◽  
Author(s):  
I. P. Johnstone ◽  
B. Castel
Keyword(s):  
Satisfactory Agreement ◽  
Giant Dipole Resonance ◽  
Energy Levels ◽  
Transition Rates ◽  
Dipole Strength ◽  
Dipole Resonance ◽  
Spectroscopic Factors ◽  
Core Excitations

The structure of 29Si is studied in a model which couples a neutron onto low-lying core states of 28Si. Very satisfactory agreement is obtained for energy levels, E2 transition rates, and spectroscopic factors. The splitting of the 28Si dipole strength is then investigated using a particle–core and hole–core interaction derived from this 29Si study, and the effect of various approximations is examined.

NUCLEAR PHOTOABSORPTION IN 208Pb BETWEEN THRESHOLD AND 140 MeV

1989 ◽  
Vol 04 (19) ◽  
pp. 5249-5259 ◽  
Author(s):  
P. QUARATI ◽  
P. P. DELSANTO ◽  
M. GUIDETTI
Keyword(s):  
Giant Dipole Resonance ◽  
Energy Region ◽  
Occupation Number ◽  
Energy Levels ◽  
Resonance Energy ◽  
Nucleon Nucleon ◽  
Photonuclear Reactions ◽  
Production Threshold ◽  
Hole Energy ◽  
Dipole Resonance

We have investigated photonuclear reactions in 208 Pb from the reaction threshold to pion production threshold. In the Giant Dipole Resonance energy region we have considered the results of a recent 1− 1p-1h continuum calculation and multiplied them, heuristically, by a factor, which includes the effect of neglected nucleon-nucleon correlations, through the occupation number probabilities of the single particle and hole energy levels. We have thus obtained a much better agreement with experiment. In the energy region above the Giant Dipole Resonance we have considered a quasi deuteron model, which contains the effect of nucleon swelling. Both this model and corresponding integrated sum rules yield a satisfactory agreement with experiment.

Shell Model and Collective Excitations in 72Ge

1973 ◽  
Vol 51 (23) ◽  
pp. 2403-2406 ◽  
Author(s):  
B. Castel ◽  
M. Micklinghoff ◽  
I. P. Johnstone
Keyword(s):  
Shell Model ◽  
Satisfactory Agreement ◽  
Energy Levels ◽  
Second Order ◽  
Order Perturbation ◽  
Collective Excitations ◽  
Model Structure ◽  
Core Excitations ◽  
Two Parameters

The importance of core excitations in the shell model structure of 72Ge is investigated in a model which couples two neutrons in the p1/2 and g9/2 subshells to the low-lying excitations of 70Ge. Particle excitations from the p3/2 and f5/2 subshells are taken into account through second-order perturbation diagrams. Satisfactory agreement is obtained for energy levels and E2 and E0 rates in 72Ge in a calculation involving essentially two parameters.

scholarly journals Electric dipole strength below the giant dipole resonance

2002 ◽  
Author(s):  
P. Mohr ◽  
T. Hartmann ◽  
K. Vogt ◽  
S. Volz ◽  
A. Zilges
Keyword(s):  
Electric Dipole ◽  
Giant Dipole Resonance ◽  
Dipole Strength ◽  
Dipole Resonance

Theoretical investigation of giant dipole resonance in 146−152Nd isotopes with QRPA

2020 ◽  
Vol 29 (07) ◽  
pp. 2050040
Author(s):  
Nilufer Demirci Saygı ◽  
Filiz Ertuğral Yamaç ◽  
Ali Kuliev
Keyword(s):  
Cross Section ◽  
Giant Dipole Resonance ◽  
Random Phase ◽  
Spherical Geometry ◽  
Strength Distribution ◽  
Text Structure ◽  
Photoabsorption Cross Section ◽  
Dipole Strength ◽  
Quasiparticle Random Phase Approximation ◽  
Dipole Resonance

We investigate the electric dipole ([Formula: see text]) structure properties of the deformed [Formula: see text]Nd nuclei in the giant dipole resonance (GDR) region within the framework of the quasiparticle random-phase approximation (QRPA). Translational and Galilean invariance (TGI) QRPA with separable isovector dipole–dipole residual interaction have been employed for the calculations. We have computed the photoabsorption cross-section and then we have compared with the experimental data. Our calculations revealed that while the photoabsorption cross-section shows a Lorentzian line in the neighborhood of spherical geometry, it starts to shift to an asymmetric shape by increasing deformation in [Formula: see text]Nd isotopes by increasing neutron number. In addition to this, we have also observed that the splitting of the [Formula: see text] strength distribution and the separation between [Formula: see text] and [Formula: see text] branches are increasing. We have calculated the contribution of the electric and magnetic parts of total dipole strength up to 20[Formula: see text]MeV for the nuclei of interest. This calculation shows that the electric part dominates the total dipole strength and [Formula: see text] excitation dominates the electric part.

Alpha Particle Emission from 16O and 20Ne in the Giant Dipole Resonance Region

1975 ◽  
Vol 53 (14) ◽  
pp. 1398-1399 ◽  
Author(s):  
D. M. Skopik ◽  
Y. M. Shin ◽  
J. J. Murphy II
Keyword(s):  
Satisfactory Agreement ◽  
Cross Sections ◽  
Alpha Particle ◽  
Giant Dipole Resonance ◽  
Virtual Photon ◽  
Resonance Region ◽  
Particle Emission ◽  
Dipole Resonance ◽  
Giant Dipole Resonance Region

The electrodisintegration cross sections, 16O(e,α0)12C,e′ and 20Ne(e,α0)16O,e′, have been measured and, by using virtual photon analysis, a comparison with photodisintegration experiments has been made. Satisfactory agreement with earlier 12C(α,γ0)16O experiments was found and the 20Ne(γ,α0)16O reaction reveals several pronounced resonances.

scholarly journals GIANT DIPOLE RESONANCE IN DEFORMED NUCLEI: DEPENDENCE ON SKYRME FORCES

2007 ◽  
Vol 16 (02) ◽  
pp. 624-633 ◽  
Author(s):  
V. O. NESTERENKO ◽  
W. KLEINIG ◽  
J. KVASIL ◽  
P. VESELY ◽  
P.-G. REINHARD
Keyword(s):  
Giant Dipole Resonance ◽  
Random Phase Approximation ◽  
Random Phase ◽  
The Self ◽  
Dipole Strength ◽  
Deformed Nuclei ◽  
Effective Masses ◽  
Dipole Resonance ◽  
Self Consistent ◽  
Basic Characteristics

The giant dipole resonance (GDR) in deformed nuclei is analyzed using the self-consistent separable random-phase-approximation (SRPA) with Skyrme forces SkT6, SkM*, SLy6 and SkI3. The deformed nuclei 150 Nd and 238 U are used as representative rare-earth and actinide samples. Dependences of the dipole strength distributions on some basic characteristics of the Skyrme functional and nuclear matter properties (isoscalar and isovector effective masses, time-odd contributions) are discussed. Particular attention is paid to the fragmentation structure of the GDR strength which is shown to depend sensitively to spin-orbit intruder states with large angular momentum.

Sign in / Sign up

Export Citation Format

Share Document