Shape coexisting intruder states in even Sn isotopes and their influence on the B4/2<1 anomaly

The normal and intruder configuration states of the even ¹¹⁴⁻¹²²Sn nuclei are described in a geometric model using a double well collective potential. It is shown that subtle changes in the potential shapes can reproduce the mass dependence of the low-lying energy levels and the associated $E0$ and $E2$ transitions. The extracted shape dynamics reveals different instances of shape coexistence with and without mixing, in all considered nuclei. This information is used to track the origin of B4/2<1 values reported for 114,122Sn isotopes, providing thus a phenomenological interpretation.