Scattering and resonance properties of the interaction of slow neutrons with the isotopes of silicon and sulfur

In¹¹⁷Te,¹¹⁹Te and¹²¹Te isomeric states withJ ^π=5/2⁺, 5/2⁺ and 7/2⁺ and half-lives of 19.1(9)ns, 2.2(2) ns and 86(6) ns, respectively, have been identified at low excitation energies using (α, 2n) reactions on enriched^115–119Sn targets. Positive parityΔJ=1 bands built on these isomeric states have been observed up to 17/2⁺. The states are interpreted as members of rotational bands built on deformation driving 5/2⁺ [402] and 7/2⁺ [404] Nilsson orbitals which overcome theN=64 subshell gap. The irregular level spacings and electromagnetic properties of the bands are well explained in Coriolis calculations. The moment of inertia parameter as function of collective angular momentum has been derived from the doubly even Te cores. The hindrance of the band head deexcitation may be caused by shape fluctuations of these transitional nuclei.