Topological self-dual configurations in a Lorentz-violating gauged O(3) sigma model

We have studied the existence of topological Bogomol'nyi-Prasad-Sommerfield or self-dual configurations in a Lorentz-violating gauged $O(3)$ nonlinear sigma model, where $CPT$-even Lorentz-violating (LV) terms were introduced in both the gauge and $\sigma $% -field sectors. As happens in the usual gauged $\sigma $ model, purely magnetic self-dual configurations are allowed, maintaining some qualitative features of the standard ones. In a more involved configuration, Lorentz violation provides new self-dual magnetic solutions carrying an electric field but a null total electric charge. In both cases, the total energy of the self-dual configurations turns out to be proportional to the topological charge of the model and to the LV parameters introduced in the $% \sigma $ sector. It is shown that the LV terms yield magnetic flux reversion as well.
Comment: revtex style, two columns, 14 pages, final and revised version published in Physical Review D