Cluster Structures in Oxygen Isotopes

Abstract

Cluster structure of 16 O, 18 O and 20 O is investigated by the antisymmettrized molecular dynamics (AMD) plus generator coordinate method (GCM). We have found the K π =0 + 2 and 0 − 1 rotational bands of 18 O that have the prominent 14 C+α cluster structure. Clustering systematics becomes richer in 20 O. We suggest the K π =0 + 2 band that is the mixture of the 12 C+α+4n and 14 C+ 6 He cluster structures, and the K π =0 − 1 band that has the 14 C+ 6 He cluster structure. The K π =0 + 3 and 0 − 2 bands that have the prominent 16 C+α cluster structure are also found.

α-cluster structure ofO18

“…configuration, which this experiment is particularly sensitive to. Similar predictions were made in [58].…”

“…Predictions for α-cluster rotational bands in 18 O have been made in [57,58].The Generator Coordinate Method (GCM) was used in [57] to investigate clustering in 18 O [57]. This is done by calculating the quadrupole moments, rms radii, and reduced α widths of the resonances using the antisymmetric 14 C g.s.…”

“…Furutachi et al studied the α-cluster structure of 18 O using AMD+GCM (antisymmetrized molecular dynamics plus the generator coordinate method) [58]. The main difference between the two calculations was that in [58] clusters emerged as a result of nucleon-nucleon and three-nucleon interaction while in [57] cluster configurations were assumed a priori. Three positive parity rotational bands are predicted in [57], but only one of them has a distinct α+ 14 C(g.s.)…”

From the Stable to the Exotic: Clustering in Light Nuclei

“…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. The corresponding moments of inertia given in Fig.…”

“…The intrinsic structure of the cluster bands is reflection asymmetric, [63] the parity projection gives an energy splitting between the partner bands. The assignments of the experimental molecular bands are supported by both the Generator-Coordinate-Method [66] and the Antisymmetrized Molecular Dynamics (AMD) calculations [67].…”