Global investigation of the fine structure of the isoscalar giant quadrupole resonance

Journal Article · Wed Apr 15 00:00:00 EDT 2009 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.79.044305· OSTI ID:21289865

Shevchenko, A; Burda, O; Kalmykov, Y; Neumann-Cosel, P von; Ponomarev, V Yu; Richter, A; Wambach, J ^[1]; Carter, J; Sideras-Haddad, E ^[2]; Cooper, G R. J. ^[3]; Fearick, R W ^[4]; Foertsch, S V; Lawrie, J J; Neveling, R; Smit, F D ^[5]; Fujita, H ^[2]; Fujita, Y ^[6]; Lacroix, D ^[7]

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1. Institut fuer Kernphysik, Technische Universitaet Darmstadt, D-64289, Darmstadt (Germany)
2. School of Physics, University of the Witwatersrand, PO Wits, Johannesburg 2050 (South Africa)
3. School of Earth Sciences, University of the Witwatersrand, PO Wits, Johannesburg 2050 (South Africa)
4. Department of Physics, University of Cape Town, Rondebosch 7700 (South Africa)
5. iThemba LABS, P. O. Box 722, Somerset West 7129 (South Africa)
6. Department of Physics, Osaka University, Toyonaka, Osaka 560-0043 (Japan)
7. GANIL, CEA and IN2P3, Boite Postale 5027, F-14076 Caen Cedex (France)

Fine structure in the region of the isoscalar giant quadrupole resonance (ISGQR) in {sup 58}Ni, {sup 89}Y, {sup 90}Zr, {sup 120}Sn, {sup 166}Er, and {sup 208}Pb has been observed in high-energy-resolution ({delta}E{sub 1/2}{approx_equal}35-50 keV) inelastic proton scattering measurements at E{sub 0}=200 MeV at iThemba LABS. Calculations of the corresponding quadrupole excitation strength functions performed within models based on the random-phase approximation (RPA) reveal similar fine structure when the mixing of one-particle one-hole states with two-particle two-hole states is taken into account. A detailed comparison of the experimental data is made with results from the quasiparticle-phonon model (QPM) and the extended time-dependent Hartree-Fock (ETDHF) method. For {sup 208}Pb, additional theoretical results from second RPA and the extended theory of finite Fermi systems (ETFFS) are discussed. A continuous wavelet analysis of the experimental and the calculated spectra is used to extract dominant scales characterizing the fine structure. Although the calculations agree with qualitative features of these scales, considerable differences are found between the model and experimental results and amongst different models. Within the framework of the QPM and ETDHF calculations it is possible to decompose the model spaces into subspaces approximately corresponding to different damping mechanisms. It is demonstrated that characteristic scales mainly arise from the collective coupling of the ISGQR to low-energy surface vibrations.

• OSTI ID: 21289865
• Journal Information: Physical Review. C, Nuclear Physics, Vol. 79, Issue 4; Other Information: DOI: 10.1103/PhysRevC.79.044305; (c) 2009 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
COMPARATIVE EVALUATIONS
COMPUTERIZED SIMULATION
COUPLING
DAMPING
ENERGY RESOLUTION
ERBIUM 166
EXCITATION
FINE STRUCTURE
GIANT RESONANCE MODEL
HARTREE-FOCK METHOD
INELASTIC SCATTERING
KEV RANGE 10-100
LEAD 208
MEV RANGE 100-1000
MIXING
NICKEL 58
NUCLEAR QUADRUPOLE RESONANCE
PROTONS
QUASIPARTICLE-PHONON MODEL
RANDOM PHASE APPROXIMATION
RESONANCE
SPECTRA
STRENGTH FUNCTIONS
SURFACES
TIME DEPENDENCE
TIN 120
YTTRIUM 89
ZIRCONIUM 90