Above threshold s-wave resonances illustrated by the 1/2(+) states in Be-9 and B-9

作者：Garrido E^*; Fedorov D V; Jensen A S

来源：Physics Letters B, 2010, 684(2-3): 132-136.

DOI：10.1016/j.physletb.2009.12.065

We solve the persistent problem of the structure of the lowest 1/2(+) resonance in Be-9 which is important to bridge the A = 8 gap in nucleosynthesis in stars. We show that the state is a genuine three-body resonance even though it decays entirely into neutron-Be-8 relative s-waves. The necessary barrier is created by "dynamical" evolution of the wave function as the short-distance alpha-He-5 structure is changed into the large-distance n-Be-8 structure. This decay mechanism leads to a width about two times smaller than table values. The previous interpretations as a virtual state or a two-body resonance are incorrect. The isobaric analog 1/2(+) state in B-9 is found to have energy and width in the vicinity of 2.0 MeV and 1.5 MeV, respectively. We also predict another 1/2(+) resonance in B-9 with similar energy and width.

• 出版日期2010-2-8