Octupole collectivity in 94Zr.

The Zr isotopes between 90Zr and 96Zr are expected to be spherical based on the almost complete subshell closures at Z = 40 and N = 50, 56. On the other hand, they have low-lying 3- states and show the characteristics of low frequency octupole oscillation which arise as a superposition of particle-hole excitations. A 380 MeV 94Zr beam from the tandem accelerator at the Japan Atomic Energy Agency (JAEA) was excited on a self-supporting natPb target. The gamma-ray detector array GEMINI-II was used to detect deexcitation gamma rays. The scattered beam (94Zr) was detected with a position-sensitive particle detector system. The gamma-ray intensities were used as an input to the least-squares search code GOSIA to determine the E3 matrix element of the first 3- excited state of 94Zr. The B(E3;0+→3-) value of 0.21(6) e2b3 in 94Zr has been obtained by Coulomb excitation experiment. [ABSTRACT FROM AUTHOR]