Structure of $^{132}_{52}$Te$_{80}$ : The two-particle and two-hole spectrum of $^{132}_{50}$Sn$_{82}$
Résumé
High-spin states in 132 Te, an isotope with two proton particles and two neutron holes outside of the 132 Sn doubly magic core, have been extended up to an excitation energy of 6.17 MeV. The prompt-delayed coincidence technique has been used to correlate states above the T 1/2 = 3.70(9) μs isomer in 132 Te to the lower states using 232 Th(7 Li ,f) at 5.4 MeV/u and the Indian National Gamma Array (INGA). With 9 Be(238 U ,f) at 6.2 MeV/u and EXOGAM γ-array coupled with the VAMOS++ spectrometer, the level scheme was extended to higher excitation energies. The high-spin positive-parity states, above J π = 10 + , in 132 Te are expected to arise from the alignment of the particles in the high-j orbitals lying close to the Fermi surface, the πg 2 7/2 , and the νh −2 11/2 configurations. The experimental level scheme has been compared with the large scale shell model calculations. A reduction in the p-n interaction strength resulted in an improved agreement with the measurements up to the spin of 15. In contrast, the comparison of the differences between the experiment and these calculations for the N = 76,78 isotones of Te and Sn shows the increasing disagreement as a function of spin, where the magnitude is larger in Te than in Sn. This behavior could possibly be attributed to the deficiencies in the p-n correlations, in addition to the n-n correlations in Sn.