Lepton Flavor Violation at FCC-ee and CEPC

Lepton flavor violating processes are highly suppressed in the Standard Model. Therefore, if observed, lepton flavor violation would be a clear indication of new physics beyond the Standard Model. We study the process e^+e^- at tree-level in the Standard Model Effective Field Theory both on the Z-pole and at higher center-of-mass energies. We show that the constraints derived from the future circular e^+e^- colliders FCC-ee and CEPC, are complementary to those obtained from low-energy tau decays at BaBar and Belle, as well as projections from Belle-II.