Unstable nuclei in coherent dissociation of relativistic nuclei 7,9Be, 10B and 10,11C

Abstract

Contribution of the unstable nuclei ⁷Be, ⁸Be and ®B into coherent dissociation events (“white” stars) of relativistic nuclei ^7,9Be, ¹⁰B and ^10,11C is under study on the basis of a nuclear track emulsion exposed to beams of the JINR Nuclotron. Distributions over the opening angle of α-pairs indicate to a simultaneous presence of virtual ⁸Be_g._s. and ⁸Be₂₊ states in the ground states of the ⁹Be and ¹⁰C nuclei. The core ⁹B is manifested in the ¹⁰C nucleus with a probability of (30 ± 4)%, Selection of the ¹⁰C “white” stars accompanied by ⁸Be_g._s. (⁹B) leads to the appearance in the excitation energy distribution of 2α2p “quartets” of the distinct peak with a maximum at 4.1 ± 0.3 MeV. ⁸Be_g._s. decays are presented in 21% 2He + 2H and 19% in the 3He of the all ¹¹C “white” stars. ⁹B_g._s. decays are identified in “white” stars ¹¹C → 2He + 2H constituting 14% of the ¹¹C “white” stars. The ⁹B nucleus. is manifested in the “white” stars ¹⁰B → 2He + 2H with a probability of (9 ± 1)%. For the ¹⁰B case yield of ⁸Be_g._s. nuclei with the respect to ⁹B is about a factor of 3 higher than ⁹B.