Self-consistent Hartree-Fock and RPA Green's function method indicate no pygmy resonance in the monopole response of neutron-rich Ni isotopes
(2014) In Physical Review C (Nuclear Physics) 90(3).- Abstract
- The random phase approximation (RPA) monopole strength and the unperturbed particle-hole excitation strength are studied, in which the strength in the continuum is properly treated without discretizing unbound particle spectra. The model is the self-consistent Hartree-Fock calculation and the RPA Green's function method with Skyrme interactions. Numerical examples are the Ni isotopes, especially Ni-68(28)40, in which an experimental observation of a low-lying peak with an appreciable amount of monopole strength at 12.9 +/- 1.0 MeV was recently reported. In the present study it is concluded that sharp monopole peaks with the width of the order of 1 MeV can hardly be expected for Ni-68 in that energy region. Instead, a broad shoulder of... (More)
- The random phase approximation (RPA) monopole strength and the unperturbed particle-hole excitation strength are studied, in which the strength in the continuum is properly treated without discretizing unbound particle spectra. The model is the self-consistent Hartree-Fock calculation and the RPA Green's function method with Skyrme interactions. Numerical examples are the Ni isotopes, especially Ni-68(28)40, in which an experimental observation of a low-lying peak with an appreciable amount of monopole strength at 12.9 +/- 1.0 MeV was recently reported. In the present study it is concluded that sharp monopole peaks with the width of the order of 1 MeV can hardly be expected for Ni-68 in that energy region. Instead, a broad shoulder of monopole strength consisting of neutron excitations to nonresonant one-particle states (called "threshold strength") with relatively low angular momenta (l, j) is obtained in the continuum energy region above the particle threshold, which is considerably lower than that of the isoscalar giant monopole resonance. In the case of monopole excitations of Ni-68 there are no unperturbed particle-hole states below 20 MeV, in which the particle expresses a neutron (or proton) resonant state. It is emphasized that in the theoretical estimate a proper treatment of the continuum is extremely important. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/4702803
- author
- Hamamoto-Kuroda, Ikuko LU and Sagawa, Hiroyuki
- organization
- publishing date
- 2014
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Physical Review C (Nuclear Physics)
- volume
- 90
- issue
- 3
- article number
- 031302
- publisher
- American Physical Society
- external identifiers
-
- wos:000342139000001
- scopus:84907143746
- ISSN
- 0556-2813
- DOI
- 10.1103/PhysRevC.90.031302
- language
- English
- LU publication?
- yes
- additional info
- The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Mathematical Physics (Faculty of Technology) (011040002)
- id
- e801f7c2-587c-4e43-b74e-3fd15bb20abc (old id 4702803)
- date added to LUP
- 2016-04-01 15:00:26
- date last changed
- 2022-04-22 06:20:24
@article{e801f7c2-587c-4e43-b74e-3fd15bb20abc,
abstract = {{The random phase approximation (RPA) monopole strength and the unperturbed particle-hole excitation strength are studied, in which the strength in the continuum is properly treated without discretizing unbound particle spectra. The model is the self-consistent Hartree-Fock calculation and the RPA Green's function method with Skyrme interactions. Numerical examples are the Ni isotopes, especially Ni-68(28)40, in which an experimental observation of a low-lying peak with an appreciable amount of monopole strength at 12.9 +/- 1.0 MeV was recently reported. In the present study it is concluded that sharp monopole peaks with the width of the order of 1 MeV can hardly be expected for Ni-68 in that energy region. Instead, a broad shoulder of monopole strength consisting of neutron excitations to nonresonant one-particle states (called "threshold strength") with relatively low angular momenta (l, j) is obtained in the continuum energy region above the particle threshold, which is considerably lower than that of the isoscalar giant monopole resonance. In the case of monopole excitations of Ni-68 there are no unperturbed particle-hole states below 20 MeV, in which the particle expresses a neutron (or proton) resonant state. It is emphasized that in the theoretical estimate a proper treatment of the continuum is extremely important.}},
author = {{Hamamoto-Kuroda, Ikuko and Sagawa, Hiroyuki}},
issn = {{0556-2813}},
language = {{eng}},
number = {{3}},
publisher = {{American Physical Society}},
series = {{Physical Review C (Nuclear Physics)}},
title = {{Self-consistent Hartree-Fock and RPA Green's function method indicate no pygmy resonance in the monopole response of neutron-rich Ni isotopes}},
url = {{http://dx.doi.org/10.1103/PhysRevC.90.031302}},
doi = {{10.1103/PhysRevC.90.031302}},
volume = {{90}},
year = {{2014}},
}