Determining the stau trilinear coupling A_τ in supersymmetric Higgs decays

. The measurement of the trilinear couplings A in the part of the Lagrangian which breaks supersymmetry softly will be a difficult experimental task. In this report the heavy Higgs decays H,A →τ_1τ_2 to stau pairs are investigated for measuring the stau trilinear coupling A_τ . Based on detailed simulations of signal and backgrounds for a specific reference point in future high luminosity e + e - linear collider experiments, it is concluded that the parameter A_τ can be determined with a precision at the 10