We consider a family of four-dimensional non-linear sigma models based on anO(5) symmetric group, whose fields take their values on the 4-sphere S4. AnSO(4)-subgroup of the model is gauged. The solutions of the model arecharacterised by two distinct topological charges, the Chern-Pontryagin chargeof the gauge field and the degree of the map, i.e. the winding number, of theS4 field. The one dimensional equations arising from the variation of theaction density subjected to spherical symmetry are integrated numerically.Several properties of the solutions thus constructed are pointed out. The onlysolution with unit Chern-Pontryagin charge are the usual BPST instantons withzero S4 winding number, while solutions with unit S4 winding number have zeroChern-Pontryagin charge.
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