‘‘Tomography’’ of the Cluster Structure of Light Nuclei via Relativistic Dissociation

Abstract

These lecture notes present the capabilities of relativistic nuclear physics for the development of the physics of nuclear clusters. Nuclear track emulsion continues to be an effective technique for pilot studies that allows one, in particular, to study the cluster dissociation of a wide variety of light relativistic nuclei within a common approach. Despite the fact that the capabilities of the relativistic fragmentation for the study of nuclear clustering were recognized quite a long time ago, electronic experiments have not been able to come closer to an integrated analysis of ensembles of relativistic fragments. The continued pause in the investigation of the "fine" structure of relativistic fragmentation has led to resumption of regular exposures of nuclear emulsions in beams of light nuclei produced for the first time at the Nuclotron of the Joint Institute for Nuclear Research (JINR, Dubna). To date, an analysis of the peripheral interactions of relativistic isotopes of beryllium, boron, carbon and nitrogen, including radioactive ones, with nuclei of the emulsion composition, has been performed, which allows the clustering pattern to be presented for a whole family of light nuclei.

From the Stable to the Exotic: Clustering in Light Nuclei

“…The first doublet (K=0 ± 2 ) has a slightly larger moment of inertia (smaller slope parameter) in 20 O, which is consistent with its interpretation as 14 C-6 He or 16 C-4 He molecular structures (they start well below the thresholds of 16.8 MeV and 12.32 MeV, respectively). The second band, for which the negative parity partner is yet to be determined, has a slope parameter slightly smaller than in 18 O. This is consistent with the study of the bands in 20 O by Furutachi et al [67], which clearly establishes parity inversion doublets predicted by AMD calculations for the 14 C-6 He cluster and 14 C-2n-α molecular structures.…”

“…E1 and M2 for the 3 + → 3 − transition and, M1 and E2 for the 3 + → 2 + transition), our calculations yield the conclusion that Γ 3 + < 0.23 eV, a value fifty times lower than known previously, which is an important result for the well studied 16 O nucleus [43]. Clustering effects in the light neutron-rich oxygen isotopes 17,18,19,20 O will also be discussed in Section 5.…”

“…Here we will only present recent results on the even-even oxygen isotopes: 18 In the assignment of the bands both the dependence of excitation energies on J(J+1) and the dependence of measured cross sections on 2J+1 [63] were considered. Slope parameters obtained in a linear fit to the excitation energies [63] indicate the moment of inertia of the rotational bands given in Fig.…”

“…Gupta [7], by Zagrebaev and W. Greiner [15] and by C. Simenel [16] where giant molecules and collinear ternary fission may co-exist [17]. Finally, signatures of α clustering have also been discovered in light nuclei surviving from ultrarelativistic nuclear collisions [18,19].…”

The Analysis of 12C on the 11B Elastic Scattering Processes at Different Energies near the Coulomb Barrier

“…11 B→2α+t is not the way to the lowest break-up barrier energy level, but this way is the leading channel [6]. The binding energy for α cluster in 12 C is 7.3 MeV [7] -7.9 MeV [6] and for t cluster in 11 B we have 11.2 MeV [7].…”