Abstract
Background:
With the recent lifetime measurements of the 2+ states in 116Te and 118Te , the evolution of the collectivity in the midshell region of the Te isotopic chain is starting to reveal itself. However, more information on the structure of the ground-state bands and the nature of the collectivity can be gathered from studying the odd-mass systems, in which lifetimes have not been extensively studied.
Purpose:
The purpose of the present work is to investigate the structure of low-lying excited states of the 𝜈ℎ11/2 band in the odd-mass systems 117Te and 119Te , that correspond to the ground-state band in even-even Te.
Methods:
Lifetimes of low-lying states in the 𝜈ℎ11/2 band of 117Te are measured for the first time and remeasured in 119Te , using the recoil distance Doppler shift technique, and analyzed with the differential decay curve method in coincidence mode.
Results:
The lifetimes and 𝐵(E2) values of the first two transitions, 15/2−→11/2− and 19/2−→15/2−, in the 𝜈ℎ11/2 band, are determined in both 117Te
and 119Te . From the lifetimes, the 𝐵(E2) values and corresponding 𝐵4/2 ratios are determined. The results are compared to systematics in both even-𝐴 and odd-𝐴 Te isotopes, as well as with theoretical results from the large-scale shell model and interacting boson model calculations.
Conclusions:
While the energy levels of 117Te
and 119Te , similarly to 118Te , exhibit textbook vibrational behavior, the unexpectedly small 𝐵4/2 ratios of these odd-mass nuclei point to a puzzling discrepancy and question the vibrational nature of these states.
With the recent lifetime measurements of the 2+ states in 116Te and 118Te , the evolution of the collectivity in the midshell region of the Te isotopic chain is starting to reveal itself. However, more information on the structure of the ground-state bands and the nature of the collectivity can be gathered from studying the odd-mass systems, in which lifetimes have not been extensively studied.
Purpose:
The purpose of the present work is to investigate the structure of low-lying excited states of the 𝜈ℎ11/2 band in the odd-mass systems 117Te and 119Te , that correspond to the ground-state band in even-even Te.
Methods:
Lifetimes of low-lying states in the 𝜈ℎ11/2 band of 117Te are measured for the first time and remeasured in 119Te , using the recoil distance Doppler shift technique, and analyzed with the differential decay curve method in coincidence mode.
Results:
The lifetimes and 𝐵(E2) values of the first two transitions, 15/2−→11/2− and 19/2−→15/2−, in the 𝜈ℎ11/2 band, are determined in both 117Te
and 119Te . From the lifetimes, the 𝐵(E2) values and corresponding 𝐵4/2 ratios are determined. The results are compared to systematics in both even-𝐴 and odd-𝐴 Te isotopes, as well as with theoretical results from the large-scale shell model and interacting boson model calculations.
Conclusions:
While the energy levels of 117Te
and 119Te , similarly to 118Te , exhibit textbook vibrational behavior, the unexpectedly small 𝐵4/2 ratios of these odd-mass nuclei point to a puzzling discrepancy and question the vibrational nature of these states.
| Original language | English |
|---|---|
| Article number | 014321 |
| Number of pages | 9 |
| Journal | Physical Review C |
| Volume | 112 |
| DOIs | |
| Publication status | Published - 21 Jul 2025 |
| Externally published | Yes |