Beyond-mean-field-model analysis of low-spin normal-deformed and superdeformed collective states ofS32,Ar

Abstract

We investigate the coexistence of spherical, deformed and superdeformed states at low spin in 32 S, 36 Ar, 38 Ar and 40 Ca. The microscopic states are constructed by configuration mixing of BCS states projected on good particle number and angular momentum. The BCS states are themselves obtained from Hartree-Fock BCS calculations using the Skyrme interaction SLy6 for the particlehole channel, and a density-dependent contact force in the pairing channel. The same interaction is used within the Generator Coordinate Method to determine the configuration mixing and calculate the properties of even-spin states with positive parity. Our calculations underestimate moments of inertia. Nevertheless, for the four nuclei, the global structural properties of the states of normal deformation as well as the recently discovered superdeformed bands up to spin 6 are correctly reproduced with regard to both the energies and the transition rates.

Cluster formations in deformed states forSi28andS32Ichikawa1, Kanada-En’yo2, Möller3 2011Phys. Rev. C299730View full textAdd to dashboardCite

“…Nuclear densities at points of special interest are also given. The calculated potential-energy curves for 28 Si and 32 S are quite similar to other calculations [5,7,8,[19][20][21]. At larger Q 2 valley-like structures appear in the 5D surface; we show curves corresponding to the bottom of the only two relatively prominent, that is deep and persistent, valleys we identify.…”

“…PACS numbers: 21.10.-k, 21.60-n, 27.30.+t A rich variety of nuclear structure data in the s-d shell region provides an excellent opportunity to investigate how a system transitions between one-body-like mean-field and twobody-like cluster structures [1,2]. Because of recent progress in experimental techniques, it has been possible to determine that strongly deformed states exist in 36 Ar and 40 Ca, by the observation of γ-ray cascades typical of rotational bands [3,4].…”

“…The SD states and the low-lying excited states have also been treated in Hartree-Fock-type (HF) self-consistent meanfield calculations [5,19], often coupled with the generatorcoordinate method (GCM) [20,21]. For 32 S, Kimura and Horiuchi suggested the existence of an SD band containing the 16 O+ 16 O cluster components, based on the antisymmetrized molecular dynamics coupled with GCM [7].…”

Tensor part of the Skyrme energy density functional. II. Deformation properties of magic and semi-magic nuclei

“…[30]. For consistency with our recent calculations [31,32], we chose a strength of −1000 MeV fm −3 for light and medium-heavy nuclei and −1250 MeV fm −3 for 186 Pb and 208 Pb.…”

Large-amplitudeQn-Qpcollectivity in the neutron-rich oxygen isotopeSeveryukhin1, Bender2, Flocard3 et al. 2007Phys. Rev. CSelf Cite3020View full textAdd to dashboardCite

“…Its strength is taken equal to −1000 MeV fm 3 in connection with two soft cutoffs at 5 MeV above and below the Fermi energies as introduced in Ref. [34].…”