Fragmentation of relativistic nuclei in peripheral interactions in nuclear track emulsion
D. A. Artemenkov, V. Bradnova, M. M. Chernyavsky, L. A. Goncharova, M. Haiduc, N. A. Kachalova, S. P. Kharlamov, A. D. Kovalenko, A. I. Malakhov, A. A. Moiseenk… 展开作者
D. A. Artemenkov, V. Bradnova, M. M. Chernyavsky, L. A. Goncharova, M. Haiduc, N. A. Kachalova, S. P. Kharlamov, A. D. Kovalenko, A. I. Malakhov, A. A. Moiseenko, G. I. Orlova, N. G. Peresadko, N. G. Polukhina, P. A. Rukoyatkin, V. V. Rusakova, V. R. Sarkisyan, R. Stanoeva, T. V. Shchedrina, S. Vokál, A. Vokálová, P. I. Zarubin, I. G. Zarubina
备注：
15 pages, 4 figures, 4 tables, conference: Relativistic nuclear physics: from Nuclotron to LHC energies, Kiev, June 18-22, 2007
核径迹乳胶技术被用来探索轻相对论核的碎裂，直到最外围的相互作用-核“白”星。一个完整的模式thererelativistic解离的$^8$ B核与目标片段伴奏。利用显著性统计方法研究了相对论离解$^{9}$ Be $\to2α$，并建立了$^{8}$ Be从0 $^+$和2 $^+$态衰变的相对贡献.显示了相对论碎裂$^{14}$ NPDMATHABMS 3 He +H和$^{22}$ Ne $\to$ 5 He的靶碎片谱。在所有这些情况下，重核上的电磁离解相对于靶质子上的碎裂的主导作用被证明。可以认为，核径迹乳胶中相对论性核的周边离解是研究与核天体物理相关的能标中最轻核和核子组成的多体系统的独特工具。
英文摘要：
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$\to2α$ 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.
A study of multiplicity distribution of singly charged, doubly charged, multi charged projectile fragments and shower particles have been carried out for the peripheral collisions in 16O-emulsion,22Ne-emulsion and 28Si-emulsion interactions at an incident momentum of (4.1-4.5) AGeV/c. Events having no target fragments have been designated as peripheral collision events. Percentage of peripheral events has been found to increase with the increase of projectile mass. Dispersion of the multiplicity distribution and its dependence on projectile mass for projectile fragments and shower particles ha…
This article is dedicated to the results of early measuring fragmentation of relativistic $^{16}$O, $^{22}$Ne, $^{28}$Si, and $^{197}$Au nuclei in a nuclear track emulsion. It has been found that there is a contribution of the unstable $^8$Be nucleus decays to $α$-particle multiplicities. These renewed measurements of nuclear track emulsion exposed to $^{84}$Kr nuclei at the energy of 950 MeV per nucleon have been analyzed and given below.
Clustering in light nuclei in fragmentation above 1 A GeV
用相对论不变量方法分析了3.3 A GeV $^{22}$ Ne在核径迹乳胶中的碎裂.用2.1 A GeV的$^{14}$ N和1.2 A GeV的$^{9}$ Be核对乳胶进行辐照，获得了少体解离的新结果。可以断言，使用不变的方法是一种有效的手段，获得的行为的系统，涉及几个He核在一个相对能量接近1兆电子伏每核子的结论。首次观测到1.2 A GeV的$^{8}$ B和$^{9}$ C核在乳胶中碎裂。所提出的结果允许一个证明核天体物理学的少体方面的发展。
Production of ensembles of $α$-particle triples associated with the Hoyle state (the second excited state of the ${}^{12}$C nucleus) in peripheral dissociation of relativistic ${}^{12}$C nuclei is studied. Stacks of nuclear track emulsion pellicles exposed to ${}^{12}$C with an energy from hundreds MeV to a few GeV per nucleon serve as the material for studies. The Hoyle state decays are reconstructed via measurement of emission angles of $α$ particles with the precision sufficient for identification of the unstable ${}^{8}$Be nucleus. The estimate of the contribution of Hoyle's state to the $…
Status and prospects of nuclear clustering studies by dissociation of relativistic nuclei in nuclear track emulsion are presented. The unstable $^{8}$Be and $^{9}$B nuclei are identified in dissociation of the isotopes $^{9}$Be, $^{10}$B, $^{10}$C and $^{11}$C, and the Hoyle state in the cases $^{12}$C and $^{16}$O. On this ground searching for the Hoyle state and more complex $α$-particle states in the dissociation of the heavier nuclei is suggested. A detailed study of a low-density baryonic matter arising in dissociation of the heaviest nuclei is forthcoming long-term problem. An analysis o…
In this work we present some results of the interaction of high energy muons with emulsion nuclei. The interaction results in emission of a number of fragments as a consequence of electromagnetic dissociation of the excited target nuclei. This excitation is attributed to absorption of photons by the target nuclei due to the intense electric field of the very fast incident muon particles. The interactions take place at impact parameters that allows ultra-peripheral collisions to take place, leading to giant resonances and hence multi-fragmentation of emulsion targets. Charge identification, ran…
In this paper, the correlation between the formation of the unstable $^{8}$Be nucleus and accompanying $α$ particles in the fragmentation of relativistic $^{16}$O, $^{22}$Ne, $^{28}$Si, and $^{197}$Au nuclei in a nuclear track emulsion is investigated. The $^{8}$Be decays are identified in a wide energy range by invariant masses calculated from 2$α$-pair opening angles. The adopted approximations are verified by data on fragmentation of $^{16}$O nuclei in a hydrogen bubble chamber in a magnetic field. An increase in the $^{8}$Be contribution to the dissociation with the growth of $α$-particle …
Measurement of 80-200 MeV/n $^{16}$O nuclear cross-section on Carbon and Polyethylene targets with the nuclear emulsion detector of the FOOT experiment
University of Bari（巴里大学）；INFN, Section of Bari（意大利国家核物理研究所巴里分部）；INFN, Section of Napoli（意大利国家核物理研究所那不勒斯分部）；INFN, Section of Perugia（意大利国家核物理研究所佩鲁贾分部）；University of Torino（都灵大学）；INFN, Section of Torino（意大利国家核物理研究所都灵分部）；Toho University（东海大学）；INFN, Section of Milano（意大利国家核物理研究所米兰分部）；University of Piemonte Orientale（皮埃蒙特大西洋大学）；Université de Strasbourg（斯特拉斯堡大学）；CNRS（法国国家科学研究中心）；IPHC（实验高能物理研究所）；University of Pisa（比萨大学）；INFN Section of Pisa（意大利国家核物理研究所比萨分部）；CNAO, National Center for Oncological Hadrontherapy（肿瘤重离子治疗国家中心）
In the events of peripheral dissociation of relativistic nuclei in the nuclear track emulsion, it is possible to study the emerging ensembles of He and H nuclei, including those from decays of unstable $^{8}$Be and $^{9}$B nuclei, as well as the Hoyle state. These extremely short-lived states are identified by invariant masses calculated from the angles in 2$α$-pairs, 2$αp$- and 3$α$-triplets in the approximation of conservation of momentum per nucleon of the primary nucleus. In the same approach, it is possible to search for more complex states. This paper explores the correlation between the…
We have studied the fragment yields emitted from the fragmentation of excited projectile nuclei in peripheral collisions of 136Xe+Pb at 1 GeV/nucleon, and measured with the high-resolution magnetic spectrometer, the Fragment Separator (FRS) of GSI. The mass, charge and isotope distributions of nuclear fragments formed in the reactions were calculated within a statistical ensemble approach and compared to the experimental data. The ensemble of excited projectilelike source nuclei were created in the framework of a previous analysis of similar reactions performed at 600 MeV/nucleon (ALADIN-exper…
The invariant mass method is used to identify the $^8$Be and $^9$B nuclei and Hoyle state formed in dissociation of relativistic nuclei in a nuclear track emulsion. It is shown that to identify these extremely short-lived states in the case of the isotopes $^9$Be, $^{10}$B, $^{10}$C, $^{11}$C, $^{12}$C, and $^{16}$O, it is sufficient to determine the invariant mass as a function of the angles in pairs and triples of He and H fragments in the approximation of the conservation of momentum per nucleon of the parent nucleus. According to the criteria established in this way, the contribution of th…
