Higgs effective Lagrangian

Authors

Adam Alloul

• Groupe de Recherche en Physique des Hautes Energies - Universite de Haute Alsace
• adam.alloul@…

Benjamin Fuks

• CERN / Institut Pluridisciplinaire Hubert Curien / Universite de Strasbourg
• benjamin.fuks@…

Veronica Sanz

• University of Sussex
• v.sanz@…

Description of the model & references

The model we have implemented is based on the description given ​here and on the parametrization adopted ​here. The Lagrangian consists of an extension of the SM Lagrangian with terms of dimension up to six comprising

• the set of CP-conserving operators describing the strongly interacting Higgs Lagrangian declared as LSILH in the model file;
• the set of operators describing the interactions of a pair of Higgs fields with a pair of leptons or quarks declared as LF1 in the model file;
• the set of operators describing the interactions of a single Higgs field with a pair of leptons or quarks and a gauge boson declared as LF2 in the model file;
• the set of operators affecting the gauge sector and possibly modifying the gauge boson self-energies and self-interactions. The variable corresponding to this piece of the Lagrangian is LBosons;
• the set of CP-violating operators declared in the variable LCP.

Model file, Lagrangian and vertices

• Main FeynRules file for the full HEL model: HEL.fr.
• Example of a Mathematica® notebook loading the model and the parameters: HEL.nb.
• Full Lagrangian as calculated by FeynRules Lagrangian
• List of all vertices as calculated by FeynRules Vertices
• UFO model file generated by FeynRules with all the new parameters set to 0.1 ufo
• CalcHep model file generated by FeynRules with all the new parameters set to 0.1 CalcHep

MaxExpressionLength is longer than the CalcHEP gui can handle. This can be fixed by opening the file c_source/chep_crt/include/syst.h and change '#define STRSIZ 2048' to '#define STRSIZ 65959' and recompile CH (make clean and then make). »

Validation