Evolution from spherical single-particle structure to stable triaxiality at high spins in Nd 140

The level structure of $ 140\atop{60} $Nd80 has been established up to spin 48 by in-beam γ-ray spectroscopy by use of the 96Zr(48Ca, 4n) reaction. High-fold γ-ray coincidences were measured with the EUROBALL spectrometer. Twelve new rotational bands have been discovered at high spins. They are interpreted as being formed in a deep triaxial minimum at ε2 ≈ 0.25 and γ ≈ 35°. Further possible configurations are assigned to the observed bands on the basis of configuration-dependent cranked Nilsson-Strutinsky calculations.