== The Higgs effective theory ==
=== Author ===
   * Claude Duhr 
      * IPPP Durham
      * claude.duhr@durham.ac.uk 

=== Description of the model ===

This model describes the effective coupling of the Higgs boson to gluons and photons. The effective theory is obtained by integrating out the top-quark loop through which the higgs couples to gluons and photons. The corresponding effective theory for a pseudo-scalar is also included.

The values of the effective couplings correspond to those given in the heft model of the !MadGraph/MadEvent distribution.
=== References ===
   * " ''Gluon final states in higgs boson decay'' ", T.G. Rizzo, Phys. Rev., vol. D22, p. 178, 1980 
   * " ''Production of a higgs pseudoscalar plus two jets in hadronic collisions'' ", R.P. Kauffman and S.V. Desai, Phys. Rev., vol. D59, p.057504, 1999 
   * " ''Amplitudes for higgs bosons plus four partons'' ", R.P. Kauffman and S.V. Desai and D. Risal, 1999 

=== Model files ===
   * [/attachment/wiki/HiggsEffectiveTheory/HiggsEffective.fr HiggsEffective.fr] This is the main file. 
   * This model needs the model file of the [wiki:StandardModel SM implementation] of !FeynRules. 
   * [/attachment/wiki/HiggsEffectiveTheory/HiggsEffective.nb HiggsEffective.nb] : This is an example Mathematica notebook that loads the model and calculates Feynman rules. 
   * The Feynman rules and the particle content are summarized in the following [/attachment/wiki/HiggsEffectiveTheory/HEFT/HiggsEffective.pdf pdf file].
=== Instructions ===

The model is loaded by merging the model files SM.fr and !HiggsEffective.fr.

The implementation allows for the use of the Feynman gauge in the SM. Feynman gauge is '''not''' supported for this model.