Three superdeformed (SD) bands have been found in Hf-168. Lifetime measurem
ents revealed a large quadrupole moment, Q(t) similar to 11.4 e b, for the
strongest band (TSD1). Theoretical calculations using the Ultimate Cranker
code predict high-spin SD minima (epsilon (2) similar to 0.43) with stable
triaxial deformations of gamma similar to +20 degrees and gamma similar to
-15 degrees. The measured Q(t) value suggests that band TSD1 corresponds, m
ost likely, to a deformation with a positive gamma value. This constitutes
the first evidence for triaxial superdeformation in an even proton system.
(C) 2001 Published by Elsevier Science B.V.