Low-energy 6D, N=(1,1) SYM effective action beyond the leading approximation

Abstract For 6D, N = ( 1 , 1 ) SYM theory formulated in N = ( 1 , 0 ) harmonic superspace as a theory of interacting gauge multiplet and hypermultiplet we construct the N = ( 1 , 1 ) supersymmetric Heisenberg-Euler-type superfield effective action. The effective action is computed for the slowly varying on-shell background fields and involves, in the bosonic sector, all powers of a constant abelian strength.