A study of the rotational side-bands in 162Dy

Abstract

Rotational side-bands in 162Dy have been studied using the 160Gd(α, 2nγ) 162Dy reaction. Seven side-bands are observed, with K π = 2 +, 2 −, (0) −, 0 +, 5 −, 4 + and (6 −). Four of these bands have collective structure at low spin: the K π = 2 + γ-vibrational band, the K π = 0 + β-vibrational band, and the K π = 2 − and (0) − octupole vibrational bands. Of the remaining bands, the 4 + band is deformation coupled while the 5 − and (6 −) bands are rotation-aligned. Several bandcrossings are observed in this nucleus. The β and γ-bands are crossed at I = 6 h ̵ and 12 h ̵ , respectively, by a highly aligned ( i 13 2 ) 2 S-band; extrapolation of this S-band to higher spin suggests that it crosses the g.s.b. between I = 18 h ̵ and 20 h ̵ . The 2 − octupole band is crossed by the 5 − band at I = 9 h ̵ and again by the (6 −) band at I = 12 h ̵ . The latter bandcrossings are discussed in terms of two-quasiparticle plus rotor calculations.