0000000000262581
AUTHOR
R. Wirowski
Evidence for a two-phonon octupole vibrational state in208Pb
Collective properties of206,208Pb have been investigated with gamma-ray spectroscopy using nuclear and electromagnetic excitation by208Pb projectiles. From the measurement of particle-particle-γ and particle-particle-γ γ coincidences a new energy level in208Pb at 5.683 MeV was observed and the data suggest an interpretation as a 2-phonon octupole vibrational state with spin 4+ or 6+. For this state one finds the same dynamical deformation parameterβ3 as for the first-excited collective 3− state. The results are compared to predictions of models which consider, in particular, the aspects of the quadrupole interaction and the interaction of the 2-particle pairing vibration with the 2-phonon o…
Electromagnetic transition probabilities in 130Ce
Abstract Lifetimes of excited nuclear states have been measured in 130Ce using the coincidence-plunger technique. The employed nuclear reaction was 98Mo(36S, 4n)130Ce at a beam energy of 150 MeV. The measurement has been performed at the NSF Daresbury using the ESSA 30 set-up. It was possible to determine lifetimes for the 4+ to 16+ states in 130Ce. The experimental B(E2) values could be well reproduced by calculations using the triaxial rotor model with β = 0.26 and γ = 21° as well as the rotation vibration model (β = 0.25).