Speaker
Description
Effective field theories (EFTs) are an important tool in particle physics. They can be used both for describing the low-energy behavior of Standard Model processes, as well as for model-independent searches for BSM physics.
Working in an EFT requires a basis of independent operators. There are two types of bases: One is the so-called on-shell basis, where each Wilson coefficient is an independent parameter to the observables. The other basis is one of independent Green's functions. It contains additional operators and is required for calculations such as renormalization and RGE evolution, which happen at the level of Green's functions.
In this talk, I present a new version of the program AutoEFT that can construct both on-shell and Green's bases for EFTs. The algorithm supports EFTs with particles of spin $0$ and spin $1/2$, as well as gauge bosons of internal $\operatorname{SU}(n)$ and $\operatorname{U}(1)$ symmetries. A group-theoretical approach is used to determine the invariants of the Lorentz and gauge groups and to eliminate the redundancies between them.
Finally, I will explore how a projection algorithm for EFT operators can be implemented. A projection algorithm can be used to define an inner product on the vector space of EFT operators. This is important because the choice of basis operators is arbitrary, so different authors may be using different bases for their calculations. A projection algorithm will facilitate the translations of results between different bases.