Physics opportunities with the SPIRAL upgrade

Lifetime plunger measurement of low-lying states in 133Ce

Non programmé

20m

Oral contribution

Orateur

Prof. Costel Petrache (CSNSM, CNRS/IN2P3, Université Paris-Sud, Orsay, France)

Description

We propose a plunger measurement to determine the lifetimes of low-lying states in 133Ce using the 116Cd(22Ne,5n)133Ce reaction and the AGATA+OUPS setup. The 133Ce nucleus has been recently studied with Gammaspehre. Several chiral bands and multiple triaxial rotational bands have been identified at high spins. From the same Gammasphere experiment a new, well populated band has been identified at low spins, which is a good candidate for transverse wobbling motion. We recall that very recently a transverse wobbling band has been identified in the oddproton nucleus 135Pr, in which a proton particle is coupled to a triaxial core. This opened new horizons for the understanding of the low-spin rotational excitations in nuclei, revealing that the wobbling motion also exists in normal-deformed lanthanides. The new band of 133Ce can be the first example of transverse wobbling in an odd-neutron nucleus in which a neutron hole is coupled to a triaxial core. However, to support such an interpretation precise lifetime measurements are necessary, to allow to disentangle between alternative interpretations. The deduced B(E2; I ->I-2)out and B(M1; I -> I-1)out will be compared with realistic QRPA calculations including the newly introduced additional interaction which couples the wobbling mode to the scissors mode. Lifetimes will be also obtained for low-lying states in 133La, an odd-proton isotone of 135Pr which is candidate for transverse wobbling, and for the even-even neighboring nuclei 132;134Ce.