== Vector-leptoquark model ==
=== Authors ===
* Michael J. Baker
* UZH, Zurich
* baker AT physik.uzh.ch
* Javier Fuentes-Martín
* UZH, Zurich
* fuentes AT physik.uzh.ch
* Gino Isidori
* UZH, Zurich
* isidori AT physik.uzh.ch
* Matthias König
* UZH, Zurich
* koenigma AT physik.uzh.ch
=== Description of the model ===
This model is an extension of the SM, featuring a vector leptoquark (''U,,1,,~('''3''','''2'''),,2/3,,''), a colored vector (''G'~('''8''','''1'''),,0,,''), and a ''Z' '' (''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-octect.[[BR]]
[/attachment/wiki/LeptoQuark/Zprime.fr Zprime.fr]: This is the Feynrules model file for the ''Z' ''.
=== 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 flavour 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' '' .