Reflection Asymmetric Shapes in the Neutron-Rich ^140,143 Ba Isotopes

Abstract

Level schemes for the neutron-rich 140q143Ba nuclei have been determined by study of prompt y-rays in spontaneous fission of 252Cf. The level pattern and enhanced E l transitions between R = + and T =bands show reflection asymmetric shapes with simplex quantum number s = $1 in 14'Ba and s = fi in 143Ba, respectively. The octupole deformation stability with spin variation has been discussed.

Reinvestigation of $s=\pm i$ octupole bands in neutron-rich141Xe

“…In even-even nuclei, the spins and parities (I p ʼs) of the levels are: I 0 , 1 , 2 , 3 , = +  for the s i =band. So far, octupole deformed bands and octupole correlations were observed in many nuclei in this region, for examples, in Ba (Z = 56) [3,[5][6][7][8][9][10], La (Z = 57) [11] and Ce (Z = 58) [6,[12][13][14][15][16][17][18][19] isotopes. However, most of the observed octupole bands belong to single simplex with s 1 = + in even-even nuclei, or s i = + or s i =in odd-A nuclei.…”