8He-6He: a comparative study of nuclear fragmentation reactions

Summary, in English

Dissociation of 227 MeV/u 8He in a carbon target has been studied in kinematically complete experiments. The data include the relative energy spectrum, angular distributions in the neutron knock-out channel (6He+n) as well as diffractive dissociation and inelastic scattering into the (6He+2n) channel. The data are compared with corresponding results from the well-known halo nucleus 6He. In both cases it is found that neutron knock-out is the dominating reaction channel. The relative energy spectrum (6He+n) shows a structure, which is interpreted as being due to the Iπ=3/2− resonance in the 7He ground state with about equal contribution from its Iπ=1/2− spin–orbit partner.



The 7He resonance shows a spin alignment similar to that observed in 5He, but with a smaller anisotropy indicating that the structure of the 8He ground state is more complicated than that of 6He.



The data in the (6He+2n) channel were used to identify resonances in the excitation energy spectrum of 8He. If the spectrum is interpreted as two overlapping resonances, the spin-parity assignment for these is found to be 2+ and 1−, respectively.

• Author: Karin Markenroth Bloch; M. Meister; Börn Eberlein; D. Aleksandrov; T. Aumann; L. Axelsson; T. Baumann; M.J.G. Borge; L.V. Chulkov; W. Dostal; Th. W. Elze; H. Emling; H. Geissel; A. Grünschloß; Margareta Hellström; J. Holeczek; B. Jonson; J. V. Kratz; R. Kulessa; A. Leistenschneider; I. Mukha; G. Münzenberg; F. Nickel; T. Nilsson; G. Nyman; M. Pfützner; V. Pribora; A. Richter; K. Riisager; C. Scheidenberger; G. Schrieder; H. Simon; J. Stroth; O. Tengblad; M. V. Zhukov
• Publishing year: 2001
• Language: English
• Pages: 462-480
• Publication/Series: Nuclear Physics, Section A
• Volume: 679
• Issue: 3-4
• Links: http://dx.doi.org/10.1016/S0375-9474(00)00372-9
• Document type: Journal article
• Publisher: Elsevier
• Status: Published
• ISBN/ISSN/Other: ISSN: 0375-9474