The variation of collective vibrational spectra with varying $N$ displayed by the $Z=52$ Te isotopes, for less than $N=82$ closed shell, are of special interest. The spectral features of the ground band and the two and three phonon excited multiplets in ${}^{118–128}\mathrm{Te}$, are studied here empirically. The state energy $E\left(2_1{}^{+}\right)$ increases, and the energy ratio $R_{4/2}$ decreases with increasing neutron number $N$. Also the $0_2{}^{+}$ state rises up sharply, and the $0_3{}^{+}$ state follows it, unlike their relation in the E(5) symmetry. It is shown that ${}^{120}\mathrm{Te}$ isotope displays the weakly deformed status, and the heavier isotopes move towards the spherical harmonic vibrator status. The interacting boson model (IBM-1) is used to reproduce these spectral features of ${}^{118–124}\mathrm{Te}$, with use of slight variation of boson energy ε and of the quadrupole interaction strength. In the microscopic approach, the dynamic pairing plus quadrupole model of Kumar and Baranger also reproduces these basic spectral features.

• Received 17 November 2022
• Revised 31 December 2022
• Accepted 22 February 2023

DOI:https://doi.org/10.1103/PhysRevC.107.034315