Special features of the 9^9Be→\to2He fragmentation in emulsion at an energy of 1.2~A~GeV

The results of investigations of the relativistic $^9$Be nucleus fragmentation in emulsion which entails the production of two He fragments of an energy of 1.2~A~GeV are presented. The results of the angular measurements of the $^9$Be$\to$2He events are analyzed. The $^9$Be$\to^8$Be+n fragmentation channel involving the $^8$Be decay from the ground (0$^+$) and the first excited (2$^+$) states to two $\alpha$ particles is observed to be predominant.Comment: 10 pages, 6 figures, conference: Conference on Physics of Fundamental Interactions, Moscow, Russia, 5-9 Dec 2005 (Author's translation

Fragmentation of relativistic nuclei in peripheral interactions in nuclear track emulsion

The technique of nuclear track emulsions is used to explore the fragmentation of light relativistic nuclei down to the most peripheral interactions - nuclear "white" stars. A complete pattern of therelativistic dissociation of a $^8$B nucleus with target fragment accompaniment is presented. Relativistic dissociation $^{9}$Be$\to2\alpha$ is explored using significant statistics and a relative contribution of $^{8}$Be decays from 0$^+$ and 2$^+$ states is established. Target fragment accompaniments are shown for relativistic fragmentation $^{14}$N$\to$3He+H and $^{22}$Ne$\to$5He. The leading role of the electromagnetic dissociation on heavy nuclei with respect to break-ups on target protons is demonstrated in all these cases. It is possible to conclude that the peripheral dissociation of relativistic nuclei in nuclear track emulsion is a unique tool to study many-body systems composed of lightest nuclei and nucleons in the energy scale relevant for nuclear astrophysics.Comment: 15 pages, 4 figures, 4 tables, conference: Relativistic nuclear physics: from Nuclotron to LHC energies, Kiev, June 18-22, 200

Topology of "white" stars in relativistic fragmentation of light nuclei

In the present paper, experimental observations of the multifragmentation processes of light relativistic nuclei carried out by means of emulsions are reviewed. Events of the type of "white" stars in which the dissociation of relativistic nuclei is not accompanied by the production of mesons and the target-nucleus fragments are considered. A distinctive feature of the charge topology in the dissociation of the Ne, Mg, Si, and S nuclei is an almost total suppression of the binary splitting of nuclei to fragments with charges higher than 2. The growth of the nuclear fragmentation degree is revealed in an increase in the multiplicity of singly and doubly charged fragments with decreasing charge of the non-excited part of the fragmenting nucleus. The processes of dissociation of stable Li, Be, B, C, N, and O isotopes to charged fragments were used to study special features of the formation of systems consisting of the lightest $\alpha$, d, and t nuclei. Clustering in form of the $^3$He nucleus can be detected in "white" stars via the dissociation of neutron-deficient Be, B, C, and N isotopes.Comment: 20 pages, 3 figures, 9 tables, conference: Conference on Physics of Fundamental Interactions, Moscow, Russia, 1-5 Mar 2004.(Author's translation