Collective excitations built on the state in 168Er
1 Max-Planck-Institut für Kernphysik, D-69117 Heidelberg, Germany
2 Division of Cosmic and Subatomic Physics, Lund University, S-22100 Lund, Sweden
Received: 25 February 1998 Communicated by B. Povh
To examine the collectivity of the previously proposed -two-phonon state in 168Er at an excitation energy of 2056 keV and of the first excited band at 1217 keV (b-band), a Coulomb excitation experiment has been carried out at the Heidelberg-Darmstadt Crystal Ball spectrometer. The B(E2) value connecting the state to the -band was remeasured to be which almost exhausts the harmonic expectation. In addition, the B(E2) values connecting the band head of the lowest lying excited band to the and states were measured to be B(E2, ) e2fm4 and B(E2, ) e2fm4; the latter is almost a factor of 10 smaller than the B(E2, value, which shows that the band head has no significant contribution of the -two-phonon state in its wave function.
21.10.Re Collective levels and giant resonances - 23.20.Ck Lifetimes and transition probabilities - 25.70.Cd Elastic and quasielastic scattering and transfer - 27.70.+q