Evanescent operators in one-loop matching computations

Effective Field Theory calculations used in countless phenomenological analyses employ dimensional regularization, and at intermediate stages of computations, the operator bases extend beyond the four-dimensional ones. The extra pieces - the evanescent operators - can ultimately be removed with a suitable renormalization scheme, resulting in a finite shift of the physical operators. Modern Effective Field Theory matching techniques relying on the method of expansion by regions have to be extended to account for this. After illustrating the importance of these shifts in two specific examples, we compute the finite shifts required to remove all evanescent operators appearing in the one-loop matching of generic ultraviolet theories to the Standard Model Effective Field Theory and elucidate the formalism for generic Effective Field Theory calculations.

Automated summary

Effective Field Theory calculations often use dimensional regularization, which extends beyond four-dimensional operator bases. The extra operators, known as evanescent operators, can be removed through suitable renormalization schemes, resulting in finite shifts of physical operators. This study focuses on extending the modern matching techniques to account for these shifts and provides calculations for removing all evanescent operators in the one-loop matching of UV theories to the Standard Model Effective Field Theory.