== Vector-leptoquark model ==

=== Authors ===
   * Michael J. Baker
      * University of Melbourne
      * michael.baker AT unimelb.edu.au
   * Javier Fuentes-Martín
      * Johannes Gutenberg University, Mainz
      * jfuentes AT uni-mainz.de
   * Gino Isidori
      * UZH, Zurich
      * isidori AT physik.uzh.ch
   * Matthias König
      * Technische Universität München
      * matthias.koenig AT tum.de

=== Description of the model ===

This model is an extension of the SM, featuring a vector leptoquark (''U,,1,,~('''3''','''1'''),,2/3,,''), a colored vector (''G'~('''8''','''1'''),,0,,''), and a SM singlet '' (''Z'~('''1''','''1'''),,0,,'') as new heavy mediators.  [[BR]]
The implementation of the model is based on ''"High-p,,T,, Signatures in Vector-Leptoquark Models''" (arXiv:1901.10480). If you use our model file please cite this reference.

=== Model Files ===

[/attachment/wiki/LeptoQuark/vector_LQ.fr  vector_LQ.fr]: This is the Feynrules model file for the vector leptoquark. [[BR]]
[/attachment/wiki/LeptoQuark/coloron.fr  coloron.fr]: This is the Feynrules model file for the vector color-octet.[[BR]]
[/attachment/wiki/LeptoQuark/Zprime.fr  Zprime.fr]: This is the Feynrules model file for the vector singlet.

=== Model Restrictions ===

[/attachment/wiki/LeptoQuark/Massless.rst  Massless.rst]: This restriction file sets all the masses and Yukawas to zero, except for the ones of the top quark (necessary to work in the 5 flavor scheme).

=== Instructions ===

The model is loaded by merging the model files {{{SM.fr}}} (in StandardModel), {{{vector_LQ.fr}}}, {{{coloron.fr}}} and {{{Zprime.fr}}}. Alternatively, one can exclude the model files {{{coloron.fr}}} or {{{Zprime.fr}}} if the user is not interested in these mediators.  [[BR]]
The implementation allows for the use of the Feynman gauge in the SM. The switch between the two gauge is achieved via {{{FeynmanGauge = True/False}}} (see StandardModel). [[BR]]
The NP interaction order has been set to 1, the same as QCD.

=== Examples ===

[/attachment/wiki/LeptoQuark/model_gen.nb  model_gen.nb]: This is an example Mathematica® notebook that loads the Feynrules model files and calculates the UFO model.  [[BR]]
[/attachment/wiki/LeptoQuark/widths.nb  widths.nb]: This is an example Mathematica® notebook that loads the Feynrules model files and calculates the Feynman rules and widths of the new vectors. 

=== Interfaces ===
This model implementation is known to work with the following interfaces:
   * [wiki:FeynArtsInterface FeynArts Interface] 
   * [wiki:MadGraphInterface MadGraph Interface] 

=== Validation ===

An alternative  Feynrules implementation for the vector leptoquark model (but with interactions to left-handed third-generation SM fermions only) is available in https://lqnlo.hepforge.org. We have cross-checked our leptoquark implementation (with ''β,,R,,^33^ = 0'') against this one, finding a perfect agreement between the two.

=== UFO model ===

[/attachment/wiki/LeptoQuark/vector_LQ_UFO.tar.gz  vector_LQ_UFO.tar.gz]: UFO model including the ''U,,1,,'', ''G' '' and ''Z' '' .