Loops and Trees in Generic 4d EFT up to operator dimension 8

Loops and Trees in Generic 4d EFT up to operator dimension 8
Yingying Li, Fermilab
Date and time: Tue, Mar 16, 2021 - 2:30pm
Location: Zoom only
Category: ACFI Seminar
Abstract:

I will talk about the tree and one-loop behavior in a generic 4d EFT of massless scalars, fermions, and vectors, with a particular eye to the high-energy limit of the Standard Model EFT at operator dimensions 6 and 8. First, I will show how to classify the possible Lorentz structures of operators and the subset of these that can arise at tree-level in a weakly coupled UV completion. Then I will show how operators contribute to tree and one-loop helicity amplitudes, exploring the impact of non-renormalization theorems through dimension 8 and helicity selection rules through the full one loop amplitude.