, O. (1984). New magnetic dipole excitation mode studied in the heavy deformed nucleus 156Gd by inelastic electron scattering.

We study a model of a deformed nucleus in which protons and neutrons are described as interacting rigid rotors with axial symmetry. The nucleus as a whole is no longer axially symmetric. A magnetic-dipole collective state describing rotational oscillations of protons against neutrons is predicted.

The mass formula El(-1)2J(W + 1 ) m J 2 = 0 is derived for a very general class of interactions with spontaneously broken supersymmetry. It shows the vanishing of the graded trace o f the square of the mass operator, with m, the mass associated with a (real) field of spin J. This mass relation is shown to be true even in the presence of explicit breaking, provided it fulfills suitable requirements.