First evidence for triaxial superdeformation in 168Hf

Three superdeformed (SD) bands have been found in 168Hf. Lifetime measurements revealed a large quadrupole moment, Qt ∼ 11.4 eb, for the strongest band (TSD1). Theoretical calculations using the Ultimate Cranker code predict high-spin SD minima (ε2 ∼ 0.43) with stable triaxial deformations of γ ∼ +20° and γ ∼ -15°. The measured Qt value suggests that band TSD1 corresponds, most likely, to a deformation with a positive γvalue. This constitutes the first evidence for triaxial superdeformation in an even proton system