scholarly journals Microscopic description of the pygmy dipole resonance in neutron-rich Ca isotopes

2018 ◽  
Vol 194 ◽  
pp. 04002
Author(s):  
N.N. Arsenyev ◽  
A.P. Severyukhin ◽  
V.V. Voronov ◽  
N.V. Giai
Keyword(s):  
Electric Dipole ◽  
Random Phase Approximation ◽  
Strength Function ◽  
Random Phase ◽  
Strength Distribution ◽  
Low Energy ◽  
Dipole Strength ◽  
Quasiparticle Random Phase Approximation ◽  
Dipole Resonance ◽  
Dipole Response

We study the effects of the phonon-phonon coupling on the low-energy electric dipole response within a microscopic model based on an effective Skyrme interaction. The finite rank separable approach for the quasiparticle random phase approximation is used. Choosing as an example the isotopic chain of Calcium, we show the ability of the method to describe the low-energy E1 strength distribution. With one and the same set of parameters we describe available experimental data for 48Ca and predict the electric dipole strength function for 50Ca.

The electric dipole response of even-even 154-164Dy isotopes

2022 ◽  
Author(s):  
Huseynqulu Quliyev ◽  
Nilufer Demirci Saygı ◽  
Ekber Guliyev ◽  
Ali Akbar Kuliev
Keyword(s):  
Cross Sections ◽  
Random Phase Approximation ◽  
Random Phase ◽  
Electric Response ◽  
Quasiparticle Random Phase Approximation ◽  
Effective Interactions ◽  
Dipole Resonance ◽  
Pygmy Dipole Resonance ◽  
Strength Functions ◽  
Dipole Response

Abstract The excitation of pygmy dipole resonance (PDR) and giant dipole resonance (GDR) in even-even 154-164Dy isotopes is examined through quasiparticle random-phase approximation (QRPA) with the effective interactions that restores the broken translational and Galilean invariances. In each isotope, an electric response emerges by showing ample distribution at energies below and above 10 MeV. We, therefore, study the transition cross sections and probabilities, photon strength functions, transition strengths, isospin character, and collectivity of the predicted E1 responses.

Electric dipole strength distribution below the E1 giant resonance in N = 82 nuclei

Open Physics ◽  
2010 ◽  
Vol 8 (6) ◽  
Author(s):  
Ekber Guliyev ◽  
Ali Kuliev ◽  
Mehmet Guner
Keyword(s):  
Experimental Data ◽  
Electric Dipole ◽  
Giant Resonance ◽  
Random Phase ◽  
Mean Field ◽  
Field Potential ◽  
Strength Distribution ◽  
Dipole Strength ◽  
Excitation Energies ◽  
Quasiparticle Random Phase Approximation

AbstractIn this study quasiparticle random-phase approximation with the translational invariant Hamiltonian using deformed mean field potential has been conducted to describe electric dipole excitations in 136Xe, 138Ba, 140Ce, 142Nd, 144Sm and 146Gd isotones. The distribution of the calculated E1 strength shows a resonance like structure at energies between 6–8 MeV exhausting up to 1% of the isovector electric dipole Energy Weighted Sum Rule and in some aspects nicely confirms the experimental data. It has been shown that the main part of E1 strength, observed below the threshold in these nuclei may be interpreted as main fragments of the Pygmy Dipole resonance. The agreement between calculated mean excitation energies as well as summed B(E1) value of the 1− excitations and the available experimental data is quite good. The calculations indicate the presence of a few prominent positive parity 1+ States in heavy N = 82 isotones in the energy interval 6–8 MeV which shows not all dipole excitations were of electric character in this energy range.

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.

ISOVECTOR PYGMY DIPOLE EXCITATION IN NEUTRON-RICH NUCLEI

2010 ◽  
Vol 25 (34) ◽  
pp. 2905-2913 ◽  
Author(s):  
KUTSAL BOZKURT
Keyword(s):  
Random Phase ◽  
Nucleon Nucleon ◽  
Strength Distribution ◽  
Experimental Results ◽  
Heavy Nuclei ◽  
Quasiparticle Random Phase Approximation ◽  
Dipole Excitation ◽  
Dipole Resonance ◽  
Pygmy Dipole Resonance ◽  
Full Interaction

We investigate isovector pygmy dipole resonance (IVPDR) for the case of neutron-rich nuclei 68 Ni , 130 Sn and 134 Sn using effective nucleon–nucleon Skyrme interaction. We use the Hartree–Fock–Bogoliubov (HFB) theory and employ the (quasiparticle) random phase approximation (Q)RPA. We calculate and compare the PDR strength in the PDR energy region for the case of density dependent central and full interaction modes for RPA and QRPA calculations. We observe that the results for the pygmy dipole resonance for neutron-rich soft nuclei 68 Ni that we consider are in reasonable agreement with their experimental results in both interactions and calculations. We also study the PDR for highly neutron-rich heavy nuclei, such as 130 Sn and 134 Sn . We see that only the QRPA calculation with full interaction is in good agreement with the experimental results for these nuclei and with a recent study in the literature. We find that the PDR strength distribution sensitively depends on the chosen interaction modes, especially for the neutron-rich heavy nuclei 134 Sn .

Hybrid random-phase-approximation–cluster model for the dipole strength function ofLi11

1991 ◽  
Vol 43 (5) ◽  
pp. R2049-R2051 ◽  
Author(s):  
N. Teruya ◽  
C. A. Bertulani ◽  
S. Krewald ◽  
H. Dias ◽  
M. S. Hussein
Keyword(s):  
Cluster Model ◽  
Random Phase Approximation ◽  
Strength Function ◽  
Random Phase ◽  
Phase Approximation ◽  
Dipole Strength

E1 STRENGTH IN LIGHT NUCLEI: SKYRME RPA ANALYSIS

2012 ◽  
Vol 21 (05) ◽  
pp. 1250041 ◽  
Author(s):  
J. KVASIL ◽  
A. REPKO ◽  
V. O. NESTERENKO ◽  
W. KLEINIG ◽  
P.-G. REINHARD
Keyword(s):  
Random Phase Approximation ◽  
Random Phase ◽  
Light Nuclei ◽  
Strong Impact ◽  
Phase Approximation ◽  
Experiment Data ◽  
Dipole Strength ◽  
Dipole Resonance ◽  
Double Folding ◽  
Acceptable Agreement

The giant dipole resonance (GDR) in N = 28 isotones (48 Ca , 50 Ti , 52 Cr , 54 Fe ) is analyzed in the framework of the Skyrme random-phase-approximation (RPA). Three Skyrme forces, SkM*, SLy6 and SV-bas, are used. The effects beyond RPA are simulated by the double folding procedure. We show that dipole strength exhibits a large collective shift, which testifies to a strong impact of the residual interaction and signals on considerable anharmonic effects. In 52 Cr , a significant pairing impact is found. For exception of 50 Ti , an acceptable agreement with the experiment data is obtained, which justifies the ability of Skyrme forces to describe GDR in light nuclei.

scholarly journals γ-ray strength function for astrophysical applications in the IAEA-CRP

2020 ◽  
Vol 239 ◽  
pp. 07005
Author(s):  
Hiroaki Utsunomiya ◽  
Stephane Goriely ◽  
Therese Renstrøm ◽  
Gry M. Tveten ◽  
Takashi Ari-izumi ◽  
...  
Keyword(s):  
Cross Sections ◽  
Random Phase Approximation ◽  
Function Method ◽  
Strength Function ◽  
Random Phase ◽  
Phase Approximation ◽  
Quasiparticle Random Phase Approximation ◽  
Hartree Fock ◽  
Γ Ray

The γ-ray strength function (γSF) is a nuclear quantity that governs photoabsorption in (γ, n) and photoemission in (n, γ) reactions. Within the framework of the γ-ray strength function method, we use (γ, n) cross sections as experimental constraints on the γSF from the Hartree-Fock-Bogolyubov plus quasiparticle-random phase approximation based on the Gogny D1M interaction for E1 and M1 components. The experimentally constrained γSF is further supplemented with the zero-limit M1 and E1 strengths to construct the downward γSF with which (n, γ) cross sections are calculated. We investigate (n, γ) cross sections in the context of astrophysical applications over the nickel and barium isotopic chains along the s-process path.

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