Spectroscopy and lifetime measurements in 134,136,138Te isotopes and implications for the nuclear structure beyond N=82

We report on spectroscopic information and lifetime measurements of even-even neutron-rich Te isotopes. Excited states were populated in fast-neutron induced fission of U-238 at the ALTO facility of IJCLab with the LICORNE neutron source and detected using the hybrid.-ball spectrometer. We provide first results on lifetimes of the 6(1)(+) state in Te-136 and the (6(1)(+)), (4(1)(+)), and (2(1)(+)) states in Te-138 and discuss the results in the context of large-scale shell-model calculations. The level schemes of Te-136 and Te-138 are revised in terms of lifetimes of their 2(1)(+), 4(1)(+) states and updated information on the (4(2)(+)) state in Te-136 is presented. In addition, previously reported data on spectroscopy and lifetimes in Te-134 are reexamined. This work provides new insights into the evolution of collectivity for Te isotopes with N = 82, 84, 86.

Automated summary

This study presents spectroscopic information and lifetime measurements of even-even neutron-rich Te isotopes, focusing on Te-136 and Te-138. The results are discussed in the context of large-scale shell-model calculations, providing new insights into the evolution of collectivity for Te isotopes with N = 82, 84, 86.