Determining the stau trilinear coupling Ar 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 → τ1τ2 to stau pairs are investigated for measuring the stau trilinear coupling Aτ. 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 Aτ can be determined with a precision at the 10% level in the region of moderate to large tan β. (orig.)