title: Effective-range approach and scaling laws for electromagnetic strength in neutron-halo nuclei.
abstract: We study low-lying multipole strength in neutron-halo nuclei. The strength depends only on a few low-energy constants: the neutron separation energy, the asymptotic normalization coefficient of the bound-state wave function, and the scattering length that contains the information on the interaction in the continuum. The shape of the transition probability shows a characteristic dependence on few scaling parameters and the angular momenta. The total E1 strength is related to the root-mean-square radius of the neutron wave function in the ground state and shows corresponding scaling properties. We apply our approach to the E1 strength distribution of 11Be.
authors.affiliation: Gesellschaft für Schwerionenforschung mbH, Darmstadt, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Typel
authors.forename: G
authors.initials: G
authors.lastname: Baur