Constraints from Maximal Supersymmetry and Positivity on EFT Amplitudes

I will describe the constraints of maximal supersymmetry on super Yang-Mills EFT tree amplitudes and show how a simple parity constraint implies that the 6-point SUSY Ward identities can only be solved when the Wilson coefficients in the 4-point amplitude obey novel non-linear constraints. When these are combined with positivity, the allowed values of the 4-point Wilson coefficients are restricted to lie in a small region shrinking (as more constraints are included) around the values for the Veneziano amplitude.