Exact Results in Quantum Theory

Effective Field Theory approach became in recent years a tool of choice in searching for and classifying (potential as yet!) experimental deviations from the Standard Model predictions for elementary particle interactions.I will review step by step how to use SM EFT extension in realistic calculations, starting from historical introduction, then discussing irreducible operator basis construction, quantization of the theory (requiring non-trivial gauge fixing conditions), transition to physical field basis, parametrization problems and automating the calculations with the use of computer tools. Time-permitting, as an example of application of such scheme I will illustrate it on sample calculation of Higgs->2 photon decay.