Cluster Structures Of Excited States Research Articles

Simulation of the Inelastic Alpha-Particle Scattering Reaction for Investigating the Cluster Structure of Excited States of 9Be

It is proposed to investigate inelastic scattering of alpha particles on the clusters of the $$^{9}{\text{Be}}$$ nucleus for determining the contribution from the cluster configurations ( $$^{8}{\text{Be}} + n$$ , $$\alpha + \alpha + n$$ , $$^{5}{\text{He}} + \alpha $$ ) to the $$^{9}{\text{Be}}$$ structure. The kinematic simulation of the $$^{9}{\text{Be}}(\alpha ,\alpha {\kern 1pt} 'n)X$$ and $$^{9}{\text{Be}}(\alpha ,\alpha {\kern 1pt} '\alpha )X$$ reactions shows that detection of the scattered alpha particle in coincidence with the particle from the breakup of a certain excited state of $$^{9}{\text{Be}}$$ allows determining the contribution from different cluster configurations to the structure of those states.

Cluster features of stable and unstable nuclei in thep-shell region

Cluster aspects in light unstable nuclei as well as light stable nuclei are discussed. We focus on cluster structures of excited states in 12C, 9Li, and 10Be. The rotation of 3α cluster gas states in 12C and the 6He+t cluster resonances in 9Li are theoretically studied.

Cluster structures of excited states in 11B

The cluster structure of excited states in 11B is investigated with a method of β-γ constrained antisymmetrized molecular dynamics in combination with the generator coordinate method. For negative-parity states, we identify a band with a 2α+t cluster structure. This band starts from the 3/2−3 state and may correspond to the experimental band observed recently. We find that the composision of the 3/2−3 state s quite similar to that of the 0+2 state in 12C.

Cluster structures of excited states in 14C

We investigate structures of excited states in 14C with a method of β-γ constraint antisymmetrized molecular dynamics in combination with the generator coordinate method. Various excited states with the developed 3α-cluster core structures are suggested in positive-and negative-parity states. In the positive-parity states, triaxial deformed and linear-chain structures are found to construct excited bands. Interestingly, 10Be+α correlation is found in the cluster states above the 10Be+α threshold energy. By applying a generalized molecular orbital model to the linear-chain state of 14C, we confirm the 10Be+α correlation.

Brueckner-AMD Method and Its Applications to Light Nuclei

We propose a new approach employing the Brueckner-AMD in which the G-matrix is calculated using the antisymmetrized molecular dynamics (AMD). Its applications to some light nuclei are demonstrated, and the high reliability of the description of the shell and cluster structures is discussed. In the conventional approach employing the G-matrix for the study of nuclear matter or the shell model, the constructed G-matrix is used to reproduce effective interactions. Therefore, the effective interactions are valid only in the model space. It is desirable for the model space to be as large as possible, but for practical reasons, a finite dimensional space is used. For this reason, the effective interaction is model dependent, 1) and one must accept the limits of its applicability. The conventional shell model calculations have failed in the description of nuclear cluster states, which are observed in the excited states around cluster thresholds. By contrast, the cluster model has been shown to provide a successful description of these states. Recent developments of the cluster model based on the antisymmetrized molecular dynamics (AMD) 2) have led to success in reproducing the various kinds of cluster structures of excited states, in addition to the shell model structure of the ground and low-lying states, without any assumption concerning cluster configurations. This result indicates that the functional space of AMD is very large; the wave functions of AMD can describe not only shell model configurations but also cluster configurations. However, to this time studies of AMD have been carried out without detailed investigations of the effective interactions. It is important to construct a framework of the G-matrix for AMD. In this letter, we propose a framework of the Brueckner-AMD to calculate the G-matrix for AMD. Since the pioneering cluster study of α + α, 3) there has been much interest in elucidating the role of the tensor force component resulting from the one-pion exchange potential (OPEP) in the α-cluster formation and the binding mechanism of the α-particle. 4) – 8) Study of the G-matrix has been carried out in association with the appearance of α-clustering and the cluster structures in the low-excitation [ (

Search for cluster structure of excited states in 14 C

We have studied three different 2n-transfer reactions on a 12C target, the 2p pick-up reaction on 16O and the 5He transfer in the reaction 9Be(7Li,d)14C. Combined with a systematic search through experimental results for transfer reactions, inelastic excitations and other data, we have established an almost complete spectroscopy for 14C up to 18 MeV excitation. We identify states with single-particle structure that have oblate shapes and states corresponding to proton excitations that are connected to oblate (triangular) cluster states. Further we list states of prolate shape which have no simple structure related to the low-lying oblate states of 12C. These are proposed to have strong \(\alpha\)-clustering and to form rotational bands as a parity inversion doublet, with high moment of inertia. With these results it is possible for the first time to identify chain states expected in the isotope 14C.