Confronting flavor symmetries and extended scalar sectors with lepton flavor violation bounds

We discuss the tension between discrete flavor symmetries and extended scalar sectors arising from lepton flavor violation experiments. The key point is that extended scalar sectors will generically lead to flavor changing neutral currents, which are strongly constrained by experiments. Because of the large parameter space in the scalar sector such models will, however, usually have no big problems with existing and future bounds (even though the models might be constrained). This changes considerably once a flavor symmetry is imposed in addition: Because of the symmetry, additional relations between the different couplings arise and cancellations become impossible in certain cases. The experimental bounds will then constrain the model severely and can easily exclude it. We consider two examples which show how these considerations are realized. The same logic should apply to a much wider class of models.