Nonaxial-octupole Y_{32} correlations in N = 150 isotones from multidimensional constrained covariant density functional theories
Abstract
The non-axial reflection-asymmetric
β
32
shape in some transfermium nuclei with N=150, namely
246
Cm,
248
Cf,
250
Fm, and
252
No are investigated with multidimensional constrained covariant density functional theories. By using the density-dependent point coupling covariant density functional theory with the parameter set DD-PC1 in the particle-hole channel, it is found that, for the ground states of
248
Cf and
250
Fm, the non-axial octupole deformation parameter
β
32
>0.03
and the energy gain due to the
β
32
distortion is larger than 300 keV. In
246
Cm and
252
No, shallow
β
32
minima are found. The occurrence of the non-axial octupole
β
32
correlations is mainly from a pair of neutron orbitals
[734]9/2
(
ν
j
15/2
) and
[622]5/2
(
ν
g
9/2
) which are close to the neutron Fermi surface and a pair of proton orbitals
[521]3/2
(
π
f
7/2
) and
[633]7/2
(
π
i
13/2
) which are close to the proton Fermi surface. The dependence of the non-axial octupole effects on the form of energy density functional and on the parameter set is also studied.