Spin-isospin rotation dynamics
  The equations for the solitons arbitrarily rotating in the ordinary and isotopic space are obtained. The wave functions of the corresponding dynamic states in the quantum case are found. The generalized matrix of the moments of inertia is degenerate for the O(2)-invariant configurations characteristic for the nucleon and delta-isobar. The equation for such configurations is established. It is shown that the spin-isospin rotation prevents the collapse of the soliton states in the SU(2) sigma-model. The entire consideration is based on the variational approach to the method of collective variables. 
V.D. Tsukanov