Anomalous properties of quadrupole collective states inTe136and beyond

Abstract

The ground and low-lying states of neutron-rich exotic Te and Sn isotopes are studied in terms of the nuclear shell model by the same Hamiltonian used for the spherical-deformed shape phase transition of Ba isotopes, without any adjustment. An anomalously small value is obtained for B͑E2;0 1 + → 2 1 + ͒ in 136 Te, consistent with a recent experiment. The levels of 136 Te up to yrast 12 + are shown to be in agreement with observed ones. It is pointed out that 136 Te can be an exceptionally suitable case for studying mixed-symmetry 1 + , 2 + , and 3 + states, and predictions are made for energies and M1 and E2 properties. Systematic trends of structure of heavier and more exotic Sn and Te isotopes beyond 136 Te are studied by the Monte Carlo shell model, presenting an unusual and very slow evolution of collectivity/deformation.

Matrix diagonalization algorithm and its applicability to the nuclear shell model

“…MS states in the vicinity of N = 82 were investigated recently within the QPM [ calculations were devoted to these states in Te isotopes [46] and in N = 80 isotones [47]. We will perform a thorough investigation of the low-energy spectroscopic properties of 132 Xe and 134 X.…”

Electromagnetic properties of the21+state in134Te: Influence of core excitation on single-particle orbits beyondStuchbery1, Allmond2, Galindo-Uribarri3 et al. 2013Phys. Rev. C376330View full textAdd to dashboardCite

“…Even so, the measured g factor has a precision that rivals traditional measurements on stable beams. Moreover, it distinguishes between the alternative models [1][2][3][4], and the precise B(E2) measured simultaneously reveals an unexpected level of quadrupole collectivity in the first excited state.…”

“…This Rapid Communication reports on the Coulomb excitation of a radioactive beam of 134 Te (T 1/2 = 42 min), the semimagic N = 82 nucleus with two protons outside the neutron-rich, double-magic nucleus 132 Sn. Despite the expected simple two-proton character of 134 Te, the theoretical predictions of the g factor of the first excited state range from 0.5 to 0.86 [1][2][3][4]. Both the gyromagnetic ratio (or g factor) of the 2 + 1 state and the reduced transition probability, B(E2; 0 + 1 → 2 + 1 ) = B(E2) ↑, were measured.…”

Importance-sampling diagonalization algorithm for large-scale shell model calculations onN=80isotones

“…The MS states in the vicinity of the N = 82 magic number were investigated within the QPM [32,56]. Large-scale shell model calculations were devoted to these states in Te isotopes [57]. As already pointed out, the same chain of N = 80 isotones considered here was studied in Ref.…”