Elsevier

Nuclear Physics A

Volume 517, Issues 3–4, 29 October 1990, Pages 599-614
Nuclear Physics A

Electromagnetic dissociation of 11li and soft dipole mode

https://doi.org/10.1016/0375-9474(90)90221-7Get rights and content

Abstract

The electromagnetic dissociation in the (11Li, 9Li) projectile fragmentation has been studied using a formalism developed by Winther and Alder. Two types of excitations of 11Li contribute to the process: One is the excitation of the 9Li core in 11Li to its first excited state and the other the excitations of the soft dipole mode where the relative motion between the 9Li core and two valence neutrons plays a prime role. The cluster-orbital shell model for the 9Li+n+n system has been worked out to describe those excited states which are relevant to the soft dipole mode. The electric dipole strength obtained at very low excitation energy, which exceeds that every observed, corresponds to about 40% of the non-energy-weighted sum rule and to about 10% of the energy-weighted sum rule. The predicted electromagnetic dissociation cross section for a Pb target is in good agreement with experiment, and the present theory strongly supports the existence of a soft dipole mode at low excitation energy of extremely neutron-rich nuclei.

References (21)

  • T. Kobayashi

    Phys. Lett.

    (1989)
  • Y. Tosaka et al.

    Nucl. Phys.

    (1990)
  • H. Sato et al.Y. Suzuki et al.
  • D.J. Millener et al.

    Phys. Rev.

    (1983)
  • D.L. Olson

    Phys. Rev.

    (1983)
  • H.H. Heckman et al.

    Phys. Rev. Lett.

    (1976)
    D.L. Olson

    Phys. Rev.

    (1981)
    J.C. Hill et al.

    Phys. Rev. Lett.

    (1988)
  • I. Tanihata

    Phys. Rev. Lett.

    (1985)
    I. Tanihata

    Phys. Lett

    (1985)
    I. Tanihata

    RIKEN-AF-NP-60

    (1987)
  • T. Kobayashi

    Phys. Rev. Lett.

    (1988)
  • P.G. Hansen et al.

    Europhys. Lett.

    (1987)
  • Y. Suzuki et al.

    Phys. Rev.

    (1988)
    Y. Suzuki et al.

    Phys. Rev.

    (1990)
There are more references available in the full text version of this article.

Cited by (0)

1

Work supported in part by the Grant-in Aid for Scientific Research of the Ministry of Education, Science and Culture, 1988–1989, Japan.

2

Present address: Semiconductor Devices Lab., Fujitsu Laboratories Ltd., Atsugi 243-01, Japan.

View full text
Copyright © 1990 Published by Elsevier B.V.