First signs of collectivity in N = 86 and 88 isotones above 132Sn

Abstract

Within the shell-model framework the low-lying states energies, E2 and M1 transitions of chains of nuclei 52 ≤ Z ≤ 60 with 82 ≤ N ≤ 88 are investigated. We use the N3LOP effective interaction derived from Effective Field Theory Potentials and phenomenologically constrained. We noticed clear collective features in N = 86 and 88 isotones, with signature of triaxial γ-bands.