Study of the Involvement of $^8$Be and $^9$B Nuclei in the Dissociation of Relativistic $^{10}$C, $^{10}$B, and $^{12}$C Nuclei

TL;DR

This study investigates how $^8$Be and $^9$B nuclei contribute to the dissociation of relativistic $^{10}$C, $^{10}$B, and $^{12}$C nuclei, revealing specific decay channels, excitation energies, and the presence of the Hoyle state.

Contribution

It provides new insights into the role of $^8$Be and $^9$B in nuclear dissociation processes and quantifies their contributions in relativistic nuclear reactions.

Findings

Identification of a peak at 4.1 MeV in excitation energy distributions.

Quantification of $^8$Be and $^9$B contributions in dissociation channels.

Observation of the Hoyle state in $^{12}$C dissociation.

Abstract

The results obtained by estimating the contribution of $^8$Be and $^9$B nuclei to the coherent dissociation of $^{10}$C, $^{10}$B, and $^{12}$C relativistic nuclei in nuclear track emulsions (``white'' stars) are presented. The selection of ``white'' stars accompanied by $^9$B leads to a distinct peak appearing in the distribution of the excitation energy of 2$\alpha$2$p$ ensembles and having a maximum at 4.1 $\pm$ 0.3 MeV. A $^8$Be nucleus manifests itself in the coherent-dissociation reaction $^{10}$B $\to$ 2He + H with a probability of (25 $\pm$ 5)\%, (14 $\pm$ 3)\% of it being due to $^9$B decays. The ratio of the branching fractions of the $^9$B + $n$ and $^9$Be + $p$ mirror channels is estimated at 6 $\pm$ 1. An analysis of the relativistic dissociation of $^{12}$C nuclei in a nuclear track emulsion revealed nine 3$\alpha$ events corresponding to the Hoyle state.