  Using a schematic solvable many-body Hamiltonian, one studies a new type of
proton-neutron excitations within a time dependent variational approach.
Classical equations of motion are linearized and subsequently solved
analytically. The harmonic state energy is compared with the energy of the
first excited state provided by diagonalization as well as with the energies
obtained by a renormalized RPA and a boson expansion procedure. The new
collective mode describes a wobbling motion, in the space of isospin, and
collapses for a particle-particle interaction strength which is much larger
than the physical value. A suggestion for the description of the system in the
second nuclear phase is made. We identified the transition operators which
might excite the new mode from the ground state.
