The majority of atomic nuclei have deformed shapes and nearly all these shapes are symmetric with respect to reflection. There are only a few reflection asymmetric pear-shaped nuclei that have been found in actinide and lanthanide regions, which have static octupole deformation. These nuclei possess an intrinsic electric dipole moment due to the shift between the center of charge and the center of mass. This manifests in the enhancement of the electric dipole transition rates. In this article, we report on the measurement of the lifetimes of the high-spin levels of the two alternating-parity bands in ${}^{100}\mathrm{Ru}$ through the Doppler shift attenuation method. The estimated electric dipole transition rates have been compared with the calculated transition rates using the triaxial projected shell model without octupole deformation and are found to be an order of magnitude enhanced. Thus, the observation of seven interleaved electric dipole transitions with enhanced rates establish ${}^{100}\mathrm{Ru}$ as possibly the first octupole deformed nucleus reported in the $A\approx 100$ mass region.

Close

PrevNext

View figure in article

• Electromagnetic transitions
• High spin states
• Nuclear shapes and moments
• Nuclear structure & decays
• 90 ≤ A ≤ 149