MULTIPHONON VIBRATIONAL STATES IN PD-106,PD-108

摘要

The nuclei Pd-106 and Pd-108 have been Coulomb excited using beams of O-16, Ni-58 and Pb-208. The data determined 25 and 31 E2 matrix elements in Pd-106 and Pd-108, respectively. The experimental data are qualitatively in agreement with the spherical-harmonic quadrupole vibrational model, but quantitatively there are large discrepancies, even for the states generally accepted to be the two-phonon vibrational states. A sum-rule method was applied to the data, the result of which implies that the vibrational quadrupole strengths of the 0(+) and 4(+) two-phonon states are fragmented and shared between several E2 matrix elements. The E2 matrix elements imply appreciable quadrupole triaxiality with a gamma-centroid of about 20 degrees. A systematic comparison is made with neighbouring Pd-isotopes and with Cd-114. [References: 47]