Superdeformation in asymmetric N>Z nucleus 40Ar

Abstract A rotational band with five γ -ray transitions ranging from 2 + to 12 + states was identified in 40 Ar. This band is linked through γ transitions from the excited 2 + , 4 + and 6 + levels to the low-lying states; this determines the excitation energy and the spin–parity of the band. The deduced transition quadrupole moment of 1.45 − 0.31 + 0.49 ± 0.15 eb indicates that the band has a superdeformed shape. The nature of the band is revealed by cranked Hartree–Fock–Bogoliubov calculations and a multiparticle–multihole configuration is assigned to the band.