Speaker
Description
Unlike any other physical system the nucleus represents a unique dual quantum many-body system. Its constituents, protons and neutrons, are assumed to be identical, except for their electric charge. They can be seen as two representations of the nucleon, with isospin components t$_z$ = ±1/2 for neutrons and protons, respectively. Under the assumption of charge independence of the strong interaction, hence invariance under rotation in the isospin space, the excitation energy spectra of mirror nuclei should be identical.
Isospin breaking effects, besides the dominating electromagnetic force, are usually studied through mirror energy differences, testing the charge symmetry and triplet energy differences, testing the charge independence of the nuclear force.
However, a more rigorous way to test isospin symmetry are electromagnetic matrix elements.
In this talk, I will present the results of our studies of isospin symmetry performed at the Radioactive Isotope Beam Factory at the RIKEN Nishina Center in Japan. I will present our study of the A = 70, T = 1 triplet where the unusually large excitation cross section of the 2$^+_1$ state of $^{70}$Kr can be interpreted in terms of a shape change in the mirror nuclei. Furthermore, I will present new results on the A=62 triplet and mirror symmetry of the A=61 quartet.
