The trace anomaly of the (2,0) tensor multiplet in background gauge fields

We study the trace anomaly of the (2,0) tensor multiplet in d=6 in the presence of a background SO(5) vector field acting as a source for the R-current. Using both a free-field theory calculation and AdS_7/CFT_6 correspondence, we find that only one of the two possible anomaly structures is non-zero and that its coefficient at strong-coupling differs by the well-known overall factor 4N^3 from the corresponding weak coupling result. We also discuss the relevance of our result to studies of the R-current anomaly in the (2,0) multiplet.