Shape ofΛhypernuclei in the (β,γ) deformation plane

Abstract

We study the shape of Λ hypernuclei in the full (β, γ) deformation plane, including both axially symmetric and triaxial quadrupole deformations. To this end, we use the constrained Skyrme Hartree-Fock+BCS method on the three-dimensional Cartesian mesh. The potential energy surface is analyzed for carbon hypernuclei as well as for sd-shell hypernuclei such as 27,29 Λ Si and 25,27 Λ Mg. We show that the potential energy surface in the (β, γ) plane is similar to each other between the hypernuclei and the corresponding core nuclei, although the addition of Λ hyperon makes the energy surface somewhat softer along the γ direction.

Quadrupole deformation(β,γ)of lightΛhypernuclei in a constrained relativistic mean field model: Shape evolution and shape polarization effect of theLü1, Zhao2, Zhou3 2011Phys. Rev. C

“…The γ deformation also changes considerably the local minima and the saddle point in the potential energy surface of heavy nuclei [55,56]. Recently Win et al have studied hypernuclei by using a SHF model with the triaxial degree of freedom included [57]. It is found that with an additional Λ hyperon no significant change occurs for the nuclear shapes except that the potential energy surface becomes softer in the γ direction.…”

“…We have performed constrained RMF calculations in the (β, γ) plane for eveneven carbon isotopes from 10 C to the drip line nucleus 22 C as well as for the hyper counterparts. Note that the study of carbon isotopes with triaxially deformed SHF models for normal nuclei [77] and hypernuclei [57] are both available, while that with the RMF model is still absent.…”

“…It is the aim of this paper to investigate the triaxial deformations of the Λ hypernuclei and the shape polarization effect of the Λ hyperon in the RMF model, as a comparative study with the SHF calculations [57].…”

Impurity Effects in Λ Hypernuclei

“…This is because the single-particle potential of the Λ is not parity symmetric due to the α+ 16 O clustering and is deeper around the 16 O cluster. It is expected that B Λ of 17 Λ O is more than 12 MeV, while there is no observation of 17 Λ O, which is much larger than that of 5 Λ He (B Λ (Exp.) = 3.12 ± 0.02 MeV [21]).…”

“…Since most nuclei manifest quadrupole deformation, it is of interest to investigate changes of nuclear deformations due to the addition of a Λ particle, which many authors have studied [7,[14][15][16][17][18][19][20].…”