Speaker
Description
Starting with the discovery of the nuclear component of cosmic rays, the nuclear track emulsion method (NTE) makes an opportunity to study the composition of the relativistic fragmentation of nuclei at high-energy accelerators. The promising potential of the relativistic approach to the analysis of ensembles of fragments was manifested in NTE exposed by nuclei at several GeV per nucleon accelerated at the JINR Synchrophasotron and Bevalac (USA) in the 1970s. Since the 2000s of the NTE method is applied in the BECQUEREL experiment at the JINR Nuclotron in respect to the cluster structure of nuclei, including radioactive ones, as well as the search for unstable nuclear-molecular states. Nucleon associations (clusters) are one of the basic phenomena in atomic nuclei structure. Their simplest observable manifestations are the lightest He and H nuclei. Superpositions of the lightest clusters and nucleons form subsequent nuclei (including unstable$^8$Be and B), which act as constituent clusters themselves for more complicated nuclear systems. The phenomena of cluster dissociations of light Be and B isotopes are discussed. Charge topology and angular spectra of fragmentation of 1.2 A GeV $^7$Be nuclei in NTE are presented. The dissociation channels $^4$He +$^3$He, 2$^3$He+ n, $^4$He + 2$^1$H are considered in detail. It is established that the events $^6$Be + n amount about to 27% in the channel $^4$He + 2$^1$H. The experimental results are compared with model data of fragmentation of such nuclei in NTE. The next topic consisted in the study of unstable states of $^9$Be and $^9$B. The experimental data for this nuclei obtained in relativistic fragmentation of carbon ($^{10}$C) and beryllium (from $^{10}$B) fragmentation in NTE. The opportunity of searching with nuclear track emulsions for more complex excitations in light nuclei - isobar-analogue states for $^9$Be and $^9$B isotopes are discussed [1-3].
References
[1] P. I. Zarubin Lecture Notes in Physics, Vol. 875, Clusters in Nuclei,
Volume 3. Springer Int. Publ., 51 (2013) [arXiv:1309.4881].
[2] D. A. Artemenkov et al., 8Be and 9B nuclei in dissociation of
relativistic 10C and 11C nuclei, EPJ Web of Conferences DOI: 10.1051/ conf/201611 0602.
[3] P. I. Zarubin et. al., Prospects of Searches for Unstable States
in Relativistic Fragmentation of Nuclei, Physics of Atomic Nuclei, 2022, Vol. 85, No. 6, pp. 528–539.
