Shell-model investigation of spectroscopic properties and collectivity in the nuclei beyond 132Sn

The recent shell-model results of even-even chains of nuclei: ^134,136,138Te, ^136,138,140Xe, ^138,140,142Ba, ^140,142,144Ce, and ^142,144,146Nd are explored in this manuscript. The low-lying states energies, E2 and M1 transitions, are investigated using the s a m e effective interaction based on the realistic effective field theory potential N3LO. Significant quadrupole correlations appear in the N =86 isotonic chain, with the signature of nonaxial γ band . This class of collectivity is interpreted within the SU(3) symmetries scheme and confirmed by constrained Hartree-Fock shell-model calculations.