Dr. Martin Hirsch

Searches for anomalous neutral triple gauge boson couplings (NTGCs) provide important tests for the gauge structure of the standard model. In SMEFT (``standard model effective field theory'') NTGCs appear only at the level of dimension-8 operators. In this talk, after some introductory discussion of EFT and ultra-violet completions for d=6 SMEFT operators, I introduce a class of SM extensions with heavy fermions and calculate their matching to $d=8$ NTGC operators. I discuss that the complete matching of UV models requires four different CP-conserving $d=8$ operators. Turning the phenomenology, despite stringent experimental constraints on NTGCs, limits on the scale of UV models are relatively weak, because their contributions are doubly suppressed (being $d=8$ and 1-loop).