On the road(s) to the Standard Model

TL;DR

This paper explores theoretical frameworks leading to the Standard Model, finding that the Standard Model Effective Field Theory uniquely approaches the SM, while other theories remain distinguishable by a finite cutoff.

Contribution

It analyzes classes of theories approaching the Standard Model and identifies the Standard Model Effective Field Theory as the primary pathway to the SM.

Findings

Standard Model Effective Field Theory is the main route to the SM.

Other theories cannot reach the SM limit and are separated by a finite cutoff.

The cutoff for theories outside the EFT class is at most 4πv/g_SM.

Abstract

Experimental measurements point at the Standard Model (SM) as the theory of electroweak symmetry breaking, but as we close in on our characterization the question arises of what limits in theory space lead to the SM. The class of theories with this property cannot be ruled out, only constrained to an ever smaller neighbourhood of the SM. In contrast, which class of theories do not posses this limit and can therefore potentially be ruled out experimentally? In this work we study both classes and find evidence to support the Standard Model Effective field theory being the single road to the Standard Model, theories that fall outside this class keeping a `minimum distance' from the SM characterized by a cut-off of at most $ 4\pi v/g_{\rm SM}$.