Recent Findings in Relativistic Dissociation of $${}^{10}$$ 10 B and $${}^{12}$$ 12 C Nuclei

Abstract

Recent findings related with the unstable nuclei 8 Be and 9 B in the coherent dissociation of relativistic nuclei 10 C, 10 B and 12 C in nuclear track emulsion ("white" stars) are highlighted The 8 Be g.s. nucleus is manifested in the coherent dissociation 10 B → 2He + H with a probability of 25 ± 5% including 14 ± 3% of 9 B decays. A probability ratio of the mirror channels 9 B + n and 9 Be + p is estimated to be 6 ± 1. Reanalysis of relativistic 12 C dissociation in lead enriched emulsion revealed nine 3α-events corresponding to the Hoyle state.

Microscopic clustering in light nuclei

“…A similar approach, e.g. examination of the properties of the fragmentation of 12 C at high energy have been explored in (Artemenkov et al, 2017). Another possibility is via α-particle knockout from the ground state.…”

The Hoyle State in Relativistic ${}^{12}$C Dissociation

“…In such an approach the contribution of the decays 9 B → 8 Bep → 2αp in relativistic dissociation of the isotopes 10 B and 10,11 C is revealed and, then, an indication to the resonance around 4 MeV in the channel 10 C → 9 Bp found [2]. This experience gave confidence to search in the relativistic dissociation 12 C → 3α for the Hoyle state (HS) or the second 12 C exited state exceeding just 378 keV the 3α-threshold [3][4][5]. The HS studies are reviewed in [6].…”

Search for decays of the $^{9}$B nucleus and Hoyle state in $^{14}$N nucleus dissociation

“…In the case of coherent dissociation of the 10 C → 2α2p nucleus, the decays of 8 Be and 9 B coincided completely, and their contribution was 30% [1]. Earlier, an unexpectedly large ratio of probability of coherent dissociation of 10 B in the mirror channels 9 Bn and 9 Bep was found amounting to 6 ± 1 [6]. It seems that the 9 Be nucleus itself is mainly absent as an ingredient of 10 B and 14 N, and instead of it there is a rarefied nuclear-molecular structure of 8 Ben.…”

“…The role of 9 B and HS remains a topical issue. The 14 N nucleus, following 10 B, belongs to an extremely small number of stable odd-odd nuclei (also 2 H, 6 Li, 50 V). The similarity of the cluster pattern of dissociation of these nuclei in general and formation of the unstable nuclei in particular is possible.…”