Scattering of the halo nucleus 11Be from a lead target at 3.5 times the Coulomb barrier energy
F. F. Duan, Y. Y. Yang, K. Wang, A. M. Moro, V. Guimarães, D. Y. Pang, J. Wang, Z. Sun, Jin Lei, A. Di Pietro, X. Liu, G. Yang, J.B. Ma, P. Ma, Shutao Xu, Zhiyong Bai, Xin-Xin Sun, Q. Hu, J. L. Lou, X. X. Xu, H.X. Li, Shu-Ya Jin, H. J. Ong, Quan Liu, Jia-Sheng Yao, Hang-Kai Qi, C. J. Lin, H. M. Jia, N.R. Ma, L. J. Sun, D.X. Wang, Y.H. Zhang, X. H. Zhou, Zhengguo Hu, X. Xu
Abstract
Angular distributions of quasielastic scattering and breakup of the neutron-rich halo nucleus 11 Be on a 208 Pb target at an incident energy of 140 MeV (about 3.5 times the Coulomb barrier) were measured at HIRFL-RIBLL. A strong suppression of the Coulomb nuclear interference peak is observed in the measured quasielastic scattering angular distribution. The result demonstrates for the first time the persistence of the strong breakup coupling effect reported so far for reaction systems involving neutron-halo nuclei at this relatively high incident energy. The measured quasielastic scattering cross sections are satisfactorily reproduced by continuum discretized coupled channel (CDCC) calculations as well as by the XCDCC calculations where the deformation of the 10 Be core is taken into account. The angular and energy distributions of the 10 Be fragments could also be well reproduced considering elastic breakup (CDCC and XCDCC) plus nonelastic breakup contributions, with the latter evaluated with the model by Ichimura, Austern and Vincent The comparison of the 10 Be energy distributions with simple kinematical estimates evidence the presence of a significant post-acceleration effect which, in the (X)CDCC frameworks, is accounted for by continuum-continuum couplings.