Shape Coexistence In Ne Isotopes And Impurity Effect Of ? Hyperon

The shape evolution and shape coexistence in nuclei are the hot topics of nuclear physics both in theoretical and experimental aspects.And the impurity effects of hyperons is one of the important issues in hypernuclear physics,which is one important branch of nuclear physics.In this work,possible shape coexistence in the Ne isotopes and the impurity effects of both the s? and p? hyperons are explored using the multidimensionally constrained relativistic-mean-field model with the PK1 parameter for the NN interaction and PK1-Y1 for the AN interaction.(1)The quadrupole deformation potential energy surfaces for Ne isotopes and the corresponding A hypernuclei are investigated in this work.It is found that 18Ne and 30Ne only exhibit one spherical energy minima duo to the N=8 and N=20 shell closure,respectively.Possible shape coexistences are predicted in 24,26,28Ne with small energy differences of 140 keV,336 keV,and 128 keV between the two local energy minima.20,22,32,34Ne also exhibit two two local energy minima both in the prolate and oblate sides.Besides,both s? and p? hyperons can increase the probabilities of shape coexistence by reducing energy differences between two local energy minima,but it risks the disappearance of one energy minimum locating at flat energy surface.(2)The nuclear deformations,nuclear r.m.s.radii,binding energies,and the density distributions in(r,z)plane for core nuclei and hypernuclei are examined to study the different impurity effects of s? and p? hyperon.The s? hyperon shows obvious shrinkage effects,which reduces the nuclear size and drives the nuclear shape to be more spherical.The p? hyperon on the 1/2-[110]orbit is prolate and makes the nuclear shape more prolate while the p? hyperon on the 3/2-[101]orbit displays oblate shape and drives the nuclei to be more oblate.Besides,the s? and p?hyperon will increase the probabilities of shape coexistence by reducing energy differences between the two local energy minima,but at the same time it risks the disappearance of one energy minimum locating at flat energy surfaces.