The Effective Standard Model after LHC Run I

TL;DR

This paper analyzes the constraints on the Standard Model extended with higher-dimensional operators after LHC Run 1, using electroweak precision tests, Higgs measurements, and triple-gauge couplings to derive model-independent limits.

Contribution

It introduces a comprehensive framework for constraining dimension-6 operators in the effective Standard Model using diverse experimental data.

Findings

Electroweak precision tests constrain operator coefficients.

Higgs and triple-gauge coupling measurements provide complementary limits.

Combined data restricts new physics effects in a model-independent way.

Abstract

We treat the Standard Model as the low-energy limit of an effective field theory that incorporates higher-dimensional operators to capture the effects of decoupled new physics. We consider the constraints imposed on the coefficients of dimension-6 operators by electroweak precision tests (EWPTs), applying a framework for the effects of dimension-6 operators on electroweak precision tests that is more general than the standard $S,T$ formalism, and use measurements of Higgs couplings and the kinematics of associated Higgs production at the Tevatron and LHC, as well as triple-gauge couplings at the LHC. We highlight the complementarity between EWPTs, Tevatron and LHC measurements in obtaining model-independent limits on the effective Standard Model after LHC Run~1. We illustrate the combined constraints with the example of the two-Higgs doublet model.