3αclustering in excited states ofC16

Abstract

The α-cluster states of 16 C are investigated by using antisymmetrized molecular dynamics. It is shown that two different types of α-cluster states exist: triangular and linear-chain states. The former has an approximate isosceles triangular configuration of α particles surrounded by four valence neutrons occupying the sd shell, while the latter has the linearly aligned α particles with (sd) 2 (pf ) 2 neutrons. It is found that the structure of the linear-chain state is qualitatively understood in terms of the 3/2 − π and 1/2 − σ molecular orbits as predicted by molecular-orbital model, but there exists a non-negligible 10 Be + α + 2n correlation. The bandhead energies of the triangular and linear-chain rotational bands are 8.0 and 15.5 MeV, and the latter is close to the 4 He + 12 Be and 6 He + 10 Be threshold energies. It is also shown that the linear-chain state becomes the yrast state at J π = 10 + with E x = 27.8 MeV owing to its very large moment of inertia comparable with hyperdeformation.

Study of cluster structures in10Be and16C neutron-rich nuclei via break-up reactions

“…Three centers molecular structures could be present in 16 C, as predicted in a very recent theoretical calculations [11], where some linear chains, also with parity-asymmetric nature (i.e. 10 Be+α+2n like configurations), and …”

Three-body decay of linear-chain states in C14

“…As already discussed in Refs. [19,22], in terms of the molecular orbit picture, this valence neutron orbit is interpreted as the π orbit which is composed of the perpendicular alignment of the p wave around the alpha cluster, as illustrated in Fig. 5(a).…”

“…Theoretical studies predict the rotational bands with the linear-chain configurations in C isotopes [12][13][14][15][16][17][18][19][20][21][22]. It was pointed out that the motion of the valence neutron can be qualitatively interpreted in terms of the molecular orbits analogous to the Be isotopes [23][24][25][26][27][28][29], which are called π and σ orbits.…”

Structure and Decay Pattern of Linear-Chain States in Neutron-Rich Carbon Isotopes

“…The linearchain (LC) structure of 3α particles, in which α particles are aligned on a straight line, is an exotic and famous cluster structure [3]. The LC structure has attracted considerable attention because the valence neutrons may stabilize it by their glue-like role [4][5][6][7][8][9][10].…”