Scale invariant low-energy effective action in N=3 SYM theory Original Research Article

Using the harmonic superspace approach we study the problem of low-energy effective action in N=3 SYM theory. The candidate effective action is a scale and γ5-invariant functional in full N=3 superspace built out of N=3 off-shell superfield strengths. This action is constructed as N=3 superfield generalization of F4/φ4 component term which is leading in the low-energy effective action and is simultaneously the first nontrivial term in scale invariant Born–Infeld action. All higher-order terms in the scale invariant Born–Infeld action are also shown to admit an off-shell superfield completion in N=3 harmonic superspace.