First excited 1/2(+) state in B-9

T. D. Baldwin, W. N. Catford, D. Mahboub, C. N. Timis, N. I. Ashwood, N. M. Clarke, N. Curtis, V. Ziman, T. A. D. Brown, S. P. Fox, B. R. Fulton, D. Groombridge, D. L. Watson, V. F. E. Pucknell, D. C. Weisser

Research output: Contribution to journalArticlepeer-review


Evidence has been found for a broad unbound state near 1 MeV excitation in B-9 that is a candidate for the long-disputed 1/2(+) mirror of the unbound 1.68 MeV state in Be-9. Reactions of Li-6+Li-6 were studied with a 60 MeV beam incident on a 240 mu g/cm(2) (LiF)-Li-6 target. The breakup fragments from the decay of the reaction products were detected in five Si-Si-CsI telescope detectors and the breakup particles were reconstructed using the technique of resonant particle spectroscopy. It is shown that contrary to a previous study, the 1/2(+) is not populated in the reaction Li-6(Li-6,t)B-9 but that it is populated via the Li-6(Li-6,d)B-10 reaction. The sequential decays of B-10 populated the channels Li-6(g.s.)+alpha, Li-6(2.186 MeV)+alpha, Be-8+d, and pn alpha alpha with the latter including (B-9+n or Be-9+p) decay from B-10. Decays through B-9 are identified and show the presence of the 1/2(+) state as a broad asymmetric peak around 0.8-1.0 MeV with Gamma approximate to 1.5 MeV.

Original languageEnglish
Article number034330
Pages (from-to)-
Number of pages7
JournalPhysical Review C
Issue number3
Publication statusPublished - 24 Sept 2012

Cite this