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HK: Physik der Hadronen und Kerne

HK 3: Electromagnetic and Hadronic Probes I

HK 3.9: Vortrag

Montag, 8. März 2004, 18:30–18:45, B

Isovector Spin-Flip Resonances in Medium-Mass and Heavy Nuclei^⋆ — •Y. Kalmykov¹, T. Adachi², G.P.A. Berg³, H. Fujita³, Y. Fujita², F. Hofmann¹, P. von Neumann-Cosel¹, V.Yu. Ponomarev¹, B. Reitz¹, A. Richter¹, A. Shevchenko¹, Y. Shimbara², and J. Wambach¹ — ¹Institut für Kernphysik, Technische Universität Darmstadt, Germany — ²Department of Physics, Osaka University, Japan — ³Research Center for Nuclear Physics, Osaka University, Japan

Recent progress in the understanding of isovector spin-flip resonances is discussed. The reaction ⁹⁰Zr(³He,t)⁹⁰Nb was studied at 0^∘ with a ³He beam of energy E₀ = 140 MeV/u. Highest energy resolution allows for the first time to unravel the fine structure of GTR in a heavy nucleus. Recently developed wavelet analysis techniques determine its characteristic energy scales which provide unique insight into the damping of resonances through internal mixing. The data also allow extraction of spin- and parity-separated level densities by means of a fluctuation analysis. The reaction ⁵⁸Ni(p^→,p^→ ′) was investigated at incident energy of 172 MeV up to 23 MeV and forward angles favoring the excitation of the spin-dipole mode in the continuum. The results are compared to state-of-the-art microscopic reaction calculations. The nuclear structure input, which takes the coupling to complex configurations into account, allows for the first time a satisfactory description of the spin-flip probabilities and cross sections over a wide excitation energy and angle range.
^⋆ Supported by the DFG under SFB 634 and 446 JAP 113/267/0-1.