Shape changes in the mirror nuclei ${}^{70}$Kr and ${}^{70}$Se

Abstract

We studied the proton-rich $T_z=-1$ nucleus ${}^{70}$Kr through inelastic scattering at intermediate energies in order to extract the reduced transition probability, $B(E2;0^{+}\to 2^{+})$. Comparison with the other members of the $A=70$ isospin triplet, ${}^{70}$Br and ${}^{70}$Se, studied in the same experiment, shows a $3\sigma$ deviation from the expected linearity of the electromagnetic matrix elements as a function of $T_z$. At present, no established nuclear structure theory can describe this observed deviation quantitatively. This is the first violation of isospin symmetry at this level observed in the transition matrix elements. A heuristic approach may explain the anomaly by a shape change between the mirror nuclei ${}^{70}$Kr and ${}^{70}$Se contrary to the model predictions.

accepted PRL

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Cited by in corpus (5)

• Shape coexistence in even-even nuclei: A theoretical overview
• Information content of the differences in the charge radii of mirror nuclei
• Shell model analysis of the $B(E2,2^{+}\to 0^{+})$'s in the A=70 T=1 triplet
• Investigation of octupole collectivity near the $A=72$ shape-transitional point
• Improved measurement of the $0_2^{+}\to 0_1^{+}$ E0 transition strength for ${}^{72}$Se using the SPICE spectrometer