Abstract

We present a practical three-step procedure of using the Standard Model effective field theory (SM EFT) to connect ultraviolet (UV) models of new physics with weak scale precision observables. With this procedure, one can interpret precision measurements as constraints on a given UV model. We give a detailed explanation for calculating the effective action up to one-loop order in a manifestly gauge covariant fashion. This covariant derivative expansion method dramatically simplifies the process of matching a UV model with the SM EFT, and also makes available a universal formalism that is easy to use for a variety of UV models. A few general aspects of RG running effects and choosing operator bases are discussed. Finally, we provide mapping results between the bosonic sector of the SM EFT and a complete set of precision electroweak and Higgs observables to which present and near future experiments are sensitive. Many results and tools which should prove useful to those wishing to use the SM EFT are detailed in several appendices.

Highlights

  • The discovery of a Standard Model (SM)-like Higgs boson [1, 2] is a milestone in particle physics

  • We present a practical three-step procedure of using the Standard Model effective field theory (SM EFT) to connect ultraviolet (UV) models of new physics with weak scale precision observables

  • This covariant derivative expansion method dramatically simplifies the process of matching a UV model with the SM EFT, and makes available a universal formalism that is easy to use for a variety of UV models

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Summary

Introduction

The discovery of a Standard Model (SM)-like Higgs boson [1, 2] is a milestone in particle physics. We study a complete set of the Higgs and EW precision observables that present and possible near future experiments can have a decent 1% or better sensitivity on These include the seven Electroweak precision observables (EWPO) S, T, U, W, Y, X, V up to p4 order in the vacuum polarization functions, the three independent triple gauge couplings (TGC), the deviation in Higgs decay widths {Γh→ff, Γh→gg, Γh→γγ, Γh→γZ , Γh→W W ∗ , Γh→ZZ∗ }, and the deviation in Higgs production cross sections at both lepton and hadron colliders {σggF , σW W h, σW h, σZh}. The general analysis we present for calculating the Higgs decay widths and production cross sections completely applies to fermionic operators

Covariant derivative expansion
Covariant evaluation of the tree-level and one-loop effective action
Covariant evaluation of the tree-level effective action
CDE of the one-loop effective action
General considerations
Evaluating the CDE and universal results
Evaluating terms in CDE
Universal results
U6 120
Example calculations
Electroweak triplet scalar
N δij δkl
Extra EW scalar doublet
A real singlet scalar
Supersymmetry and light scalar tops
Xt2 2 m2t g2 c2β h2t
Kinetic mixing of gauge bosons
Running of Wilson coefficients and choosing an operator set
When is RG running important?
Choosing an operator set in light of RG running analysis
Popular operator bases in the literature
Mapping Wilson coefficients onto observables
Electroweak precision observables
Deviations in Higgs decay widths
Detailed derivation
Deviations in Higgs production cross sections
Summary of results
A Supplemental details for the CDE
CDE for fermions and gauge bosons
Useful identities
B Universality of Magnetic Dipole Term
Λ2 8cW W h

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