Narrow Results

It is discussed that the recently observed 0⁺ state at 13.5 MeV in ¹⁶O can be a good candidate of the 4α condensate. The 4α condensed state which is theoretically obtained in the vicinity of the 4α threshold is shown to have a relatively large α decay width, which is in well agreement with the value measured for the 0⁺ state at 13.5 MeV. The analysis of inelastic form factor of electron scattering to the 4α condensed state is made by artificially varying the size of the 4α condensate. Similarly to the case of Hoyle state, only the magnitude of the form factor is found to depend on its size, while the position of maximum and minimum are not changed.

An examination of the role of the cluster in nuclear reactions is made in the longstanding case of ¹²C+¹²C cluster resonances in ²⁴Mg. A description of both resonant scattering and breakup measurements can be found in terms of shape isomeric cluster structures.

We have studied the ground state bulk properties of magnesium isotopes using axially symmetric relativistic mean field formalism. The BCS pairing approach is employed to take care of the pairing correlation for the open shell nuclei. The contour plot of the nucleons distribution are analyzed at various parts of the nucleus, where clusters are located. The presence of an ¹⁶O core along bubble like α-particle(s) and few nucleons are found in the Mg isotopes.

The results of application of the Cluster Channels Orthogonal Functions Method in combination with the R-matrix theory for calculating the cross-sections of the reactions induced by ⁶Li + ²H collisions are presented. As part of this work, first, very high lying resonances that have a decisive influence on the cross-sections of these reactions were identified. Second, for the first time in the framework of a theoretical study of nuclear reactions, to the cross-sections of all binary reactions pass through one and the same compound nucleus were computed using a consistent unified theoretical approach. The yield of sequential tripartition reactions is also a subject of this study.

The possibilities of using modern ab initio approaches to describe various cluster and decay characteristics of light nuclei and nuclear reactions induced by their collisions, the limits of these possibilities and prospects for expanding these boundaries are discussed. The quality of the description of the spectra of nuclear energy levels, the probabilities of emission of nucleons and clusters by resonant states, the amplitudes of the reduced decay widths of these states and the asymptotic normalization coefficients of bound states are analyzed. It is demonstrated that the results of ab initio calculations of the above characteristics can in many cases be useful for describing and predicting cross-sections for resonant nuclear reactions and analyzing the results of their measurements.

An examination of dilute, cluster, states in the nuclei ¹²C and ¹⁰Be is made. Decay correlations are used to characterise the spins of excited states in both nuclei. In addition, measurements of the breakup into its cluster constituents, 2α+2p, of the super-Borromean nucleus ¹⁰C nucleus is reported.

This contribution describes the latest developments in the field of light nuclei and explores how the tendency of nucleons to cluster into α-particle subunits influences their structure. In particular there is a focus on the structure of the nucleus ¹²C and in turn its link to nucleosynthesis and the formation of organic life.

The large scale modern configuration-interaction shell model with realistic effective Hamiltonians is used to study nuclear clustering phenomena. The many-nucleon configurations and the corresponding fractional parentage and cluster coefficients are used to build the translationally invariant wave functions of the alpha-cluster channels. The cluster spectroscopic factors satisfying the orthogonality conditions of the respective cluster channels are evaluated. The presented study of ¹⁶O exemplifies the approach. The distribution of clustering and electric quadrupole strength is examined. The results are compared with the experimentally available data.