Fine structure in the energy region of the isoscalar giant quadrupole resonance: Characteristic scales from a wavelet analysis

• Published in: Physical review letters Vol. 93; no. 12; pp. 122501.1 - 122501.4
• Main Authors: SHEVCHENKO, A, CARTER, J, NEVELING, R, PONOMAREV, V. Yu, RICHTER, A, SIDERAS-HADDAD, E, SMIT, F. D, WAMBACH, J, FEARICK, R. W, FÖRTSCH, S. V, FUJITA, H, FUJITA, Y, KALMYKOV, Y, LACROIX, D, LAWRIE, J. J, VON NEUMANN-COSEL, P
• Format: Journal Article
• Language: English
• Published: Ridge, NY American Physical Society 17-09-2004
• Subjects: Exact sciences and technology; Giant resonances; Nuclear physics; Nuclear reactions: general; Nuclear Theory; Physics; Resonance reactions; Fine structure; Wavelet transforms; Microscopic model; Quadrupoles; Giant resonances
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/physrevlett.93.122501

Fine structure in the energy region of the isoscalar giant quadrupole resonance in nuclei is observed in high-resolution proton scattering experiments at iThemba LABS over a wide mass range. A novel method based on wavelet transforms is introduced for the extraction of scales characterizing the fine structure. A comparison with microscopic model calculations including two-particle two-hole (2p2h) degrees of freedom identifies the coupling to surface vibrations as the main source of the observed scales. A generic pattern is also found for the stochastic coupling to the background of the more complex states.