Islands of Shape Coexistence: Theoretical Predictions and Experimental Evidence

Parameter-free theoretical predictions based on a dual shell mechanism within the proxy-SU(3) symmetry of atomic nuclei, as well covariant density functional theory calculations using DDME2 indicate that shape coexistence (SC) particle-hole excitation cannot occur everywhere nuclear chart but is restricted islands lying regions 7–8, 17–20, 34–40, 59–70, 96–112, 146–168 protons or neutrons. Systematics data for even-even nuclei possessing K=0 (beta) and K=2 (gamma) bands support existence these islands, which appears whenever bandhead 02+ first excited state ground band 21+ lie close in energy, with characterized by below found center islands. In addition, simple leading to multiple-shape briefly discussed.