  The nonlinear O(3) sigma-model in (2+1) dimensions with an additional
potential term admits solutions called Q-lumps, having both topological and
Noether charges. We consider in 3+1-dimensional spacetime the theory with
Q-lumps on a domain wall in the presence of spin-orbit interaction in the bulk
and find interaction effects for a two-particle solution through perturbation
theory and adiabatic approximation.
