New experimental results on in-beam gamma spectroscopy of neutron rich boron isotopes are presented for 17B and its neutron removal fragments 14,15B, after scattering with a H2 target. A gamma transition for 17B is observed at 1089±15 keV. The fragment 15B is observed abundantly associated with a gamma transition of 1336±10 keV. This suggests for the first time a core-excited structure for 17B thereby providing a new insight into its structure. Observations for 12,14B are also presented. The data set provides a useful systematic study of first excited states of neutron rich boron isotopes showing the dramatic drop in excitation energy beyond N = 8.
|ジャーナル||Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics|
|出版ステータス||出版済み - 2 24 2005|
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