E. M. Baum

Two-phonon character of the lowest J pi =1(-) state of 142Nd.

The decay properties of the 3424-keV 1{sup {minus}} state in {sup 142}Nd, which has long been interpreted as a member of the quadrupole-octupole two-phonon quintet, and of the lowest 3{sup {minus}} state, the octupole phonon, have been examined with the ({ital n},{ital n}{prime}{gamma}) reaction. {gamma}-ray branching ratios of these states have been determined, and level lifetimes have been measured by the Doppler-shift attenuation method. These data provide strong support for interpreting the 1{sup {minus}} state as having a significant two-phonon 2{sup +}{direct_product}3{sup {minus}} component.

Two-phonon character of the lowest {ital J}{sup {pi}}=1{sup {minus}} state of {sup 142}Nd

The decay properties of the 3424-keV 1{sup {minus}} state in {sup 142}Nd, which has long been interpreted as a member of the quadrupole-octupole two-phonon quintet, and of the lowest 3{sup {minus}} state, the octupole phonon, have been examined with the ({ital n},{ital n}{prime}{gamma}) reaction. {gamma}-ray branching ratios of these states have been determined, and level lifetimes have been measured by the Doppler-shift attenuation method. These data provide strong support for interpreting the 1{sup {minus}} state as having a significant two-phonon 2{sup +}{direct_product}3{sup {minus}} component.

Two-phonon character of the lowestJπ=1−state ofNd142

The decay properties of the 3424-keV 1{sup {minus}} state in {sup 142}Nd, which has long been interpreted as a member of the quadrupole-octupole two-phonon quintet, and of the lowest 3{sup {minus}} state, the octupole phonon, have been examined with the ({ital n},{ital n}{prime}{gamma}) reaction. {gamma}-ray branching ratios of these states have been determined, and level lifetimes have been measured by the Doppler-shift attenuation method. These data provide strong support for interpreting the 1{sup {minus}} state as having a significant two-phonon 2{sup +}{direct_product}3{sup {minus}} component.

Doppler Shift Lifetime Measurements at Low Recoil Velocities and Mixed‐Symmetry States in 134Ba

It is shown that the low recoil energy DSAM provides reliable lifetimes in heavy nuclei. By applying the (n,n’γ) reaction combined with DSAM to 134Ba, a great amount of new information was obtained, including level lifetimes of two mixed‐symmetry 2+ states. These data are compared with IBM‐2 calculations.

Search for various collective excitation modes with the (n, n’γ) reaction

It is demonstrated that combination of the (n,n’γ) reaction and the Doppler Shift Attenuation Method is an extremely useful tool to identify various kinds of low energy collective excitations. Evidences for double octupole and quadrupole-octupole modes are presented in96Zr and144Sm nuclei. Newly measured transition rates of the 2+ mixed-symmetry states in the134Ba O(6) nucleus are reported.

Evidence for Octupole-Octupole and Quadrupole-Octupole Excitations in Spherical Nuclei

The nuclei 96Zr and 144Sm have been studied with the (n,n ’γ) reaction, and lifetimes of many states have been extracted from the observed doppler shifts of the deexciting γ rays. A large number of fast El transitions have been observed, and the identification of possible members of the octupole-octupole and quadrupole-octupole multiplets in these nuclei has been made.