arXiv:1308.2817·v4·Nuclear Experiment
Electromagnetic M1 transition strengths from inelastic proton scattering: The cases of 48Ca and 208Pb
J. Birkhan (1)🇩🇪 · H. Matsubara (2,3)🇯🇵 · P. von Neumann-Cosel (1)🇩🇪 · N. Pietralla (1,4)🇩🇪 · V.Yu. Ponomarev (1)🇩🇪 · A. Richter (1)🇩🇪 · A. Tamii (2)🇯🇵 · J. Wambach (1,4) ((1) Institut für Kernphysik, Technische Universität Darmstadt, Darmstadt, Germany, (2) Research Center for Nuclear Physics, Osaka University, Ibaraki, (3) Tokyo Women's Medical University (4) GSI Helmholtzzemtrum für Schwerionenforschung, Darmstadt, Germany)🇩🇪
Abstract
Inelastic proton scattering at energies of a few hundred MeV and extreme forward angles selectively excites the isovector spin-flip M1 (IVSM1) resonance. A method based on isospin symmetry is presented to extract its electromagnetic transition strength from the (p,p') cross sections. It is applied to 48Ca, a key case for an interpretation of the quenching phenomenon of the spin-isospin response, and leads to a M1 strength consistent with an older (e,e') experiment excluding the almost two times larger value from a recent (\gamma,n) experiment. Good agreement with electromagnetic probes is observed in 208Pb suggesting the possibility to extract systematic information on the IVSM1 resonance in heavy nuclei.
Comments: 6 pages, 4 figures