Isovector soft dipole mode in 6Be

Abstract

By using the 1H(6Li,6Be)n charge-exchange reaction, continuum states in 6Be were populated up to E_t=16 MeV, E_t being the 6Be energy above its three-body decay threshold. In kinematically complete measurements performed by detecting alpha+p+p coincidences, an E_t spectrum of high statistics was obtained, containing approximately ~5x10^6 events. The spectrum provides detailed correlation information about the well-known 0^+ ground state of 6Be at E_t=1.37 MeV and its 2^+ state at E_t=3.05 MeV. Moreover, a broad structure extending from 4 to 16 MeV was observed. It contains negative parity states populated by Delta L=1 angular momentum transfer without other significant contributions. This structure can be interpreted as a novel phenomenon, i.e. the isovector soft dipole mode associated with the 6Li ground state. The population of this mode in the charge-exchange reaction is a dominant phenomenon for this reaction, being responsible for about 60% of the cross section obtained in the measured energy range.

8 pages, 7 figures

References in corpus (4)

• Radioactive decays at limits of nuclear stability
• On tadpoles and vacuum redefinitions in String Theory
• The ${}^8$He and ${}^{10}$He spectra studied in the $(t$,$p)$ reaction
• Three-body decay of ${}^6$Be

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• From Coulomb excitation cross sections to non-resonant astrophysical rates in three-body systems: ${}^{17}$Ne case
• Three-body correlations in direct reactions: Example of ${}^6$Be populated in $(p,n)$ reaction