Proton inelastic scattering reveals deformation in He-8

Holl M., Kanungo R., Sun Z. H., Hagen G., Lay J. A., Moro A. M., ...More

PHYSICS LETTERS B, vol.822, 2021 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 822
  • Publication Date: 2021
  • Doi Number: 10.1016/j.physletb.2021.136710
  • Journal Name: PHYSICS LETTERS B
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Chemical Abstracts Core, INSPEC, zbMATH, Directory of Open Access Journals
  • Eskisehir Osmangazi University Affiliated: No


A measurement of proton inelastic scattering of He-8 at 8.25A MeV at TRIUMF shows a resonance at 3.54(6) MeV with a width of 0.89(11) MeV. The energy of the state is in good agreement with coupled cluster and no-core shell model with continuum calculations, with the latter successfully describing the measured resonance width as well. Its differential cross section analyzed with phenomenological collective excitation form factor and microscopic coupled reaction channels framework consistently reveals a large deformation parameter beta(2) = 0.40(3), consistent with no-core shell model predictions of a large neutron deformation. This deformed double-closed shell at the neutron drip-line opens a new paradigm. (C) 2021 Published by Elsevier B.V.