Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userCluster structure of 21Ne and 21Na
221
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
We study the cluster structure of 21Ne and 21Na within the framework of the cluster shell model (CSM) and show that they have a complex cluster structure with the coexistence of a 20Ne+n, 20}Ne+p structure and a 19Ne+2n, 19}F+2p structure. Seven rotational bands are identified in 21Ne and four in 21Na and assigned to single-particle cluster states, single-hole cluster states and vibrational states. The single-particle states are associated with the 20Ne+n and 20Ne+p cluster structure, while the single-hole states are associated with the 19Ne+2n and 19F+2p structure.
rate research
Read More
We review recent studies of the cluster structure of light nuclei within the framework of the algebraic cluster model (ACM) for nuclei composed of k alpha-particles and within the framework of the cluster shell model (CSM) for nuclei composed of k alpha-particles plus x additional nucleons. The calculations, based on symmetry considerations and thus for the most part given in analytic form, are compared with experiments in light cluster nuclei. The comparison shows evidence for Z_2, D_{3h} and T_d symmetry in the even-even nuclei 8Be (k=2), 12C (k=3) and 16O (k=4), respectively, and for the associated double groups Z_2 and D_{3h} in the odd nuclei 9Be, 9B (k=2, x=1) and 13C (k=3, x=1), respectively.
We study the cluster structure of 20Ne and show that the available experimental data can be well described by a bi-pyramidal structure with D(3h) symmetry. Strong evidence for the occurrence of this symmetry comes from the observation of all nine expected vibrational modes (3 singly degenerate and 3 doubly degenerate) and of six (singly degenerate) double vibrational modes. 20Ne appears to be another example of the simplicity in complexity program, in which simple spectroscopic features arise out of a complex many-body system.
On the basis of an extended antisymmetrized molecular dynamics calculation, we study the cluster structure and the of the 0+ and 1- states of 18O. We discuss that several different kinds of cluster states appear in the excitation spectrum, and their monopole and dipole transitions are interesting fingerprints of unique cluster structure. We show that the monopole/dipole transitions are enhanced for the 14C+alpha cluster states, while they are hindered for the molecular-orbit state. We also point out that the ratio of the electric and isoscalar monopole transition strengths gives a good hint for the structure of the excited states.
We use a microscopic multicluster model to investigate the structure of $^{10}$Be and of $^{11}$Be. These nuclei are described by $alpha+alpha+n+n$ and $alpha+alpha+n+n+n$ configurations, respectively, within the Generator Coordinate Method (GCM). The 4- and 5-body models raise the problem of a large number of generator coordinates (6 for $^{10}$Be and 9 for $^{11}$Be), which requires specific treatment. We address this issue by using the Stochastic Variational Method (SVM), which is based on an optimal choice of the basis functions, generated randomly. The model provides good energy spectra for low-lying states of both nuclei. We also compute rms radii and densities, as well as electromagnetic transition probabilities. We analyze the structure of $^{10}$Be and of $^{11}$Be by considering energy curves, where one of the generator coordinates is fixed during the minimization procedure.
It is shown that the rotational band structure of the cluster states in 12C and 16O can be understood in terms of the underlying discrete symmetry that characterizes the geometrical configuration of the alpha-particles, i.e. an equilateral triangle for 12C, and a regular tetrahedron for 16O. The structure of rotational bands provides a fingerprint of the underlying geometrical configuration of alpha-particles. Finally, some first results are presented for odd-cluster nuclei.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
