Radiative decays of the 16.6 and 16.9 MeV states in Be-8 and tests of the conservation of the vector current in the A=8 multiplet

May, 1995
10 pages
Published in:
  • Phys.Rev.C 51 (1995) 2778-2788,
  • Phys.Rev.C 52 (1995) 3509-3509 (erratum)

Citations per year

19952002200920162023012345
Abstract: (APS)
We measured the He4(α,γ) cross section at θγ=90° across the 16.6 and 16.9 MeV resonances in Be8 and obtained angular distributions on the peaks of both resonances. The decays of the 16 MeV doublet to the 3.0 MeV 2+ final state have an (isovector E2)/(isovector M1) mixing ratio of (0.01±0.03), an (isoscalar E2)/(isovector M1) mixing ratio of (0.21±0.04), and an isovector M1 width of (2.80±0.18) eV. Our result for the isovector E2 strength disagrees markedly with previous work. We observe ground-state E2 decays of both members of the doublet. We use our results, plus existing Li8 and B8 β-decay data, to test the conservation of the vector current and to constrain the second-class induced-tensor form factor. Finally, we compare our results to shell-model calculations.
  • 27.20.+n
  • 24.80.-x
  • 23.20.Js