Coulomb Displacement Energies from Isobaric Analogue Resonances

Long, D.D.; Richard, Patrick; Moore, C. F.; Fox, J. D.

doi:10.1103/physrev.149.906

Cited by 55 publications

(6 citation statements)

References 26 publications

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“…Mainly even-A nuclei are reached in these reactions. Excitation functions for resonance reactions 15,16,18,[26][27][28][29][30][31][32][33][34][35] such as elastic or inelastic proton scattering via the IAS as well as one-nucleon pickup 12) or stripping 36) have also been used to study IAS. Mainly odd-A nuclei are reached in these reactions.…”

Section: Data Basementioning

confidence: 99%

Spreading widths of isobaric analog states and the isovector giant monopole resonance

1987

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A global analysis of the experimental spreading widths F ~ of 65 isobaric analog states (IAS) in the range A = 110 to 238 has been performed assuming isospin mixing via the Coulomb force with T<= T0-1 doorway states mediated by coupling to the (To-D-component of the giant isovector monopole resonance (IVM). Excellent agreement has been achieved over the entire range, thus establishing general smooth trends for the parameters describing the resonance. The excitation energy of the resonance, E(IVM)= Vo/A 1/3-(To+ 1)Vt/A was found to reproduce the IAS data with V o in the range 155 to 170 MeV and V~ ~ 55 MeV. These values are taken from recent theoretical estimates of Auerbach and the extreme hydrodynamical estimate of Bohr, Damgaard and Mottelson. The charge-dependent matrix elements were found factors of two to three stronger than hydrodynamic or microscopic estimates, but in almost perfect agreement with an expression based on sum rules derived by Lane and Mekjian. A strength-function approach developed by MacDonald and Birse for the damping widths of isovector monopole resonances was successfully employed. However, it became necessary to introduce an explicit dependence on nuclear deformation to describe a splitting of the IVM strength due to coupling to the fl-vibration component of the isovector quadrupole resonance (IVQ). The postulated fl-dependence describes the strong increase with neutron excess of the spreading widths for several rare-earth nuclei, and an essentially one-parameter fit to all experimental spreading widths gives x2/f ~ 1.2. It is further concluded that the density of doorway states which are responsible for the isospin mixing is much lower than the density of all underlying states of lower isospin with the same spin and parity as the IAS, and the ratio decreases exponentially with increasing excitation energy.

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Section: Data Basementioning

confidence: 99%

Spreading widths of isobaric analog states and the isovector giant monopole resonance

1987

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“…Such a linear fitting was performed in the 1960s and was found to work very well [33], which is characterized by the deviations from the measured E c values lying within ±150 keV.…”

Section: Experimental Coulomb Displacement Energymentioning

confidence: 92%

“…By using the A 1/3 scaling of nuclear radii, the CDE for the T = 1/2 mirror nuclei can be expressed as 6e 2 Z < /5A 1/3 [32]. Apart from the shell, deformation and pairing effects, CDE can be fitted by an empirical linear formula with two parameters B 1 and B 2 [33,34]:…”

Section: Experimental Coulomb Displacement Energymentioning

confidence: 99%

“…No systematic variations that can be attributed to shell, deformation, or pairing effects were observed. We note, however, that no data were included for the range Z < /A 1/3 ≈ 7.8-8.8 [33], corresponding to the fp-shell nuclei with A = 63-75. It is well known that the deformation can lead to modifications of single-particle states and cause qualitative changes in the structure, and therefore could alter the linear dependence of CDE on Z < /A 1/3 .…”

Section: Experimental Coulomb Displacement Energymentioning

confidence: 99%

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A survey of Coulomb displacement energies and questions on the anomalous behavior in the upper ${\sf fp}$-shell

Sun

Zhang

et al. 2014

J. Phys. G: Nucl. Part. Phys.

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The recent advances in nuclear mass measurement have sparked discussions on the isospin-symmetry breaking reflected in the Coulomb displacement energy (CDE). The current data suggested that the regular phase of the odd-even staggering in CDE for the T = 1/2 mirror nuclei persists up to A = 67 and changes at A = 69. Shell-model calculations using the modern GXPF1A and JUN45 effective interactions with a proper treatment of the Coulomb and isospin-nonconserving forces cannot describe the observation. Inspired by recent work (Kaneko 2013 Phys. Rev. Lett. 110 172505), we investigate the systematic behavior of CDE along the N = Z line up to the heaviest available masses. Starting from A ≈ 65, a systematic deviation is observed between the experimental data and the model estimations assuming the nucleus as a homogeneously charged sphere. Possibilities that may resolve the conflict between the experimental mass and theoretical expectations for the 69 Br-region are discussed, and new mass experiments are called for.

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“…carried out by the analogue resonance method with observations being made in both the proton [Lo66] and neutron exit channels [Ha66].…”

Section: Extensive Investigations Of Coulomb Displacement Energies Hamentioning

confidence: 99%

Isobaric analogue resonance studies in some rare-earth nuclei

et al. 1973

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The theme of the work is a study of isobaric analogue reson ances in heavy nuclei of the rare-earth region. After an introductory chapter describing the physical concepts associated with the analogue resonance phenomenon, the thesis is divided into two parts: part A which describes cross-section measurements of analogue resonances in elastic and inelastic proton scattering and part B which covers beam optics calculations which were performed in preparation for the use of the ANU polarised ion source for further analogue resonance studies. Unfortunately, experimental difficulties with the source have prevented any polarisation measurements through analogue resonances being carried out.

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Coulomb Displacement Energies from Isobaric Analogue Resonances

Cited by 55 publications

References 26 publications

Spreading widths of isobaric analog states and the isovector giant monopole resonance

Spreading widths of isobaric analog states and the isovector giant monopole resonance

A survey of Coulomb displacement energies and questions on the anomalous behavior in the upper ${\sf fp}$-shell

Isobaric analogue resonance studies in some rare-earth nuclei

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