Nuclear structure of ¹²⁷Te studied with (n, γ) and (d, p) reactions and interpreted with IBFM and QPM

The nuclear structure of ¹²⁷Te has been investigated with the ¹²⁶Te (n, γγ) ¹²⁷Te reaction using thermal neutrons and with the ¹²⁶Te (d, p) ¹²⁷Te reaction at E_d = 20 MeV. About 190 levels were identified in a region to 4.1 MeV excitation energy, in most cases including spin, parity and γ-decay. The γ-decay scheme after neutron capture is essentially complete containing about 100% of the population of the 11/2^- isomer and of the ground state. The thermal neutron capture cross section and isomer production of the 11/2^- state at 88.3 keV were determined to be 0.44(6) b and 0.069(10) b, respectively. The neutron binding energy was determined to be 6287.6(1) keV. A significant number of the (d, p) angular distributions of cross section and asymmetry are anomalous with respect to the distorted-wave Born-approximation calculations and could be accounted for by inelastic multi-step mechanisms. The observed strong correlation of the (d, p) and primary (n, γ) strengths gives evidence for the direct neutron capture process which is mainly responsible for the primary population of 16 levels. The experimental level scheme is compared with predictions of the interacting boson-fermion model and of the quasiparticle phonon model.