The ${}^8$Be nucleus and the Hoyle state in dissociation of relativistic nuclei

Abstract

The possibility of recording fragmentation events of relativistic nuclei in a nuclear emulsion, discovered back in the pioneering era of cosmic ray physics, opens up the prospect of using this method to study extremely cold ensembles of H and He nuclei in the interests of developing the physics of nuclear clustering and, possibly, expanding the scenarios of nuclear astrophysics. The results of the BECQUEREL experiment at JINR, obtained on unstable states in the relativistic dissociation of nuclei in a nuclear emulsion providing complete detection of fragments with record resolution are presented. According to the invariant masses calculated from the emission angles in the fragmentation cone, the decays of ${}^8$Be(0${}^{+}$), ${}^8$Be(2${}^{+}$), ${}^9$Be(1.7), ${}^9$B, ${}^6$Be, ${}^{12}$C(0${}_2^{+}$) or the Hoyle state and ${}^{12}$C(3${}^{-}$) have been identified. The contribution of ${}^8$Be(0${}^{+}$), ${}^9$B and ${}^{12}$C(0${}_2^{+}$) increases rapidly with the $\alpha$-particle multiplicity. Their structure and the diversity of parent nuclei suggest the fusion of the latter. The usage of automated microscopy for an analysis of exposures at the JINR NICA accelerator complex becomes a modern basis to apply the nuclear emulsion method.

arXiv commentThe review has been prepared on the occasion of the 70th anniversary of JINR in March 2026 (https://nsr.jinr.int/)

References in corpus (34)

• Quantum Monte Carlo calculations of A=8 nuclei
• Ab initio calculation of the Hoyle state
• Microscopic Clustering in Light Nuclei
• Structure and rotations of the Hoyle state
• Concepts of alpha-particle condensation
• Status of Alpha-Particle Condensate Structure of the Hoyle State
• Emergent geometry and duality in the carbon nucleus
• Experimental investigation of $\alpha$-condensation in light nuclei
• Candidates for the 5$\alpha$ condensed state in ${}^{20}$Ne
• Fragmentation and Multifragmentation of 10.6A GeV Gold Nuclei
• Nonlocalized Clustering and Evolution of Cluster Structure in Nuclei
• Fragmentation of relativistic oxygen nuclei in interactions with a proton
• Invariant-mass spectroscopy of ${}^{18}$Ne, ${}^{16}$O, and ${}^{10}$C excited states formed in neutron transfer reactions
• Characterization of the proposed 4-α cluster state candidate in 16O
• "Tomography" of the cluster structure of light nuclei via relativistic dissociation
• Alpha-cluster Condensations in Nuclei and Experimental Approaches for their Studies
• Peripheral interactions of relativistic ${}^{14}$N nuclei with emulsion nuclei
• Unstable states in dissociation of relativistic nuclei. Recent findings and prospects of researches
• Systematic investigation of projectile fragmentation using beams of unstable B and C isotopes
• Nuclear track emulsion in search for the Hoyle-state in dissociation of relativistic ${}^{12}$C nuclei
• Correlation in formation of ${}^8$Be nuclei and $\alpha$-particles in fragmentation of relativistic nuclei
• The Hoyle Family: The search for alpha-condensate states in light nuclei
• Secondary nuclear fragment beams for investigations of relativistic fragmentation of light radioactive nuclei using nuclear photoemulsion at Nuclotron
• Dissociation of relativistic ${}^{10}$C nuclei in nuclear track emulsion
• Irradiation of Nuclear Track Emulsions with Thermal Neutrons, Heavy Ions, and Muons
• Prospects of searching for unstable nucleus states in relativistic nuclear fragmentation
• Search for decays of the ${}^9$B nucleus and Hoyle state in ${}^{14}$N nucleus dissociation
• Study of the Involvement of ${}^8$Be and ${}^9$B Nuclei in the Dissociation of Relativistic ${}^{10}$C, ${}^{10}$B, and ${}^{12}$C Nuclei
• An enhancement of formation of unstable ${}^8$Be nucleus with the growth of $\alpha$-particle multiplicity in fragmentation of relativistic nuclei
• Highlights of Unstable States in Relativistic Dissociation of Light Nuclei in Nuclear Emulsion
• Cosmophysical aspects of relativistic nuclear fragmentation
• Toward ternary fission accompanied by the ${}^8$Be nucleus
• Exposure of Track Detectors in Xenon Ion Beams in NICA Accelerator Complex
• Current problems of studying relativistic dissociation of light nuclei in nuclear emulsion