Deformation dependence of low lying M1 strengths in even Nd isotopes

Explanation of the puzzle of 164Dy scissors

The solution of TDHFB equations by Wigner Function Moments method with the isovectorisoscalar coupling taken into account leads to the prediction of the new type of nuclear spin scissors mode. It turns out that the lower group of M1 excitations in 164Dy, which is usually not included in the systematics of the scissors mode, can be quite naturally attributed to this new type of scissors.

E2 decay strength of the M1 scissors mode of ^{156}Gd and its first excited rotational state

The E2/M1 multipole mixing ratio δ_{1→2} of the 1_{sc}^{+}→2_{1}^{+} γ-ray decay in ^{156}Gd and hence the isovector E2 transition rate of the scissors mode of a well-deformed rotational nucleus has been measured for the first time. It has been obtained from the angular distribution of an artificial quasimonochromatic linearly polarized γ-ray beam of energy 3.07(6) MeV scattered inelastically off an isotopically highly enriched ^{156}Gd target. The data yield first direct support for the deformation dependence of effective proton and neutron quadrupole boson charges in the framework of algebraic nuclear models. First evidence for a low-lying J^{π}=2^{+} member of the rotational band of states on top of the 1^{+} band head is obtained, too, indicating a significant signature splitting in the K=1 scissors mode rotational band.