Search for the Second Excited 11/2⁻ State and Weak-Coupling Schema in ¹¹⁷Sn

Abstract

The second excited 11/2⁻ state in ¹¹⁷Sn has been searched for by four different single-neutron transfer reactions, (d, t), (p, d), (d, p) and (³He, α). The state has been found at E_ex=1.589 MeV, very near to the 13/2⁻ and 15/2⁻ states observed in an in-beam γ-ray study. These very closely degenerate states are possible three members of the quintet of the weak-coupling scheme [h_11⁄2×2⁺] in this nucleus.