== The Next-To-Minimal Supersymmetric Standard Model ==
=== Author ===

[http://www.cern.ch/fuks Benjamin Fuks]
   * IPHC Strasbourg / University of Strasbourg 
   * fuks@cern.ch
 
=== Description of the model & references ===

Our NMSSM implementation in !FeynRules is general in the sense that it is keeping all the flavour-violating and helicity-mixing terms in the Lagrangian and also all the possible additional CP-violating phases. In order to deal in a transparent way with the more than 100 parameters, our implementation follows the commonly used universal set of conventions provided by the Supersymmetry Les Houches Accord.

   * [http://inspirebeta.net/search?ln=en&p=find+a+ellwanger+and+a+teixeira&f=&action_search=Search&sf=&so=d&rm=&rg=25&sc=0&of=hb Phys. Rept. 496 (2010) 1-77]: U. Ellwanger, C. Hugonie, A.M.Teixeira, ''The Next-to-Minimal Supersymmetric Standard Model''.
   * [http://inspirebeta.net/search?ln=en&p=arXiv%3A0801.4321&f=&action_search=Search JHEP 0807 (2008)  002]: A. Djouadi ''et al'', ''Benchmark scenarios for the NMSSM''.
   * [http://www.slac.stanford.edu/spires/find/hep/www?rawcmd=FIND+T+SUSY+LES+HOUCHES+and+j+JHEP&FORMAT=www&SEQUENCE= JHEP 0407 (2004) 36]: P. Skands ''et al'', ''SUSY Les Houches accord: Interfacing SUSY spectrum calculators, decay packages, and event generators'' ''.''
   * [http://www.slac.stanford.edu/spires/find/hep/www?rawcmd=FIND+T+SUSY+LES+HOUCHES+and+j+comput+phys+commun&FORMAT=www&SEQUENCE= Comput.Phys.Commun.180 (2009) 8]: B. C. Allanach ''et al'', ''SUSY Les Houches Accord 2.'' 

=== Model files ===

   * [/attachment/wiki/NMSSM/nmssm.fr nmssm.fr]: MSSM implementation using the superspace module (compatible with !FeynRules 1.6.x)
   * [/attachment/wiki/NMSSM/p1.dat p1]: parameter file to be read, associated to the sps1a scenario. In the case of the Whizard interface, this [/attachment/wiki/MSSM/p1_wo.dat parameter file] must be used instead.
   * [/attachment/wiki/NMSSM/NMSSM.nb NMSSM.nb]: Example of a Mathematica® notebook loading the model and the parameters. 

=== Specific instructions ===

   * The switch __FeynmanGauge__ allows to choose between Feynman and unitarity gauge.
   * The flags __$CKMDiag__ and __$MNSDiag__, being set to __True__ or __False__, allow for CKM and PMNS matrices different from the identity or not. 
   * A parameter file __must__ be loaded before running the model, or all the parameters would have a value of -1 (__ReadLHAFile[Input->"myfile"]__). 

=== Optimized matrix element generator models for sps1a (removal of all zero terms in the vertices) and TeX interface output ===
|| file ||The model files for !CalcHep.||
|| file ||The model files for !FeynArts.||
|| file ||The model files for !MadGraph 4.||
||[/attachment/wiki/NMSSM/p1_ufo.tgz p1_ufo.tgz]||The model files in UFO format (e.g. for !MadGraph 5).||
|| file ||The model files for Whizard.||
||[/attachment/wiki/NMSSM/p1_tex.tgz p1_tex.tgz]||LaTeX output.||
The Sherpa interface is not supported.

=== Validation ===

* The present '''NMSSM model''' has been validated against the first NMSSM implementation in !FeynRules, using component fields. We calculate the Feynman rules associated to the difference of the old and the new Lagrangian, and obtains an empty set of rules.
* The '''old NMSSM implementation''' has been validated as follow. We have compared of the built-in !Whizard model files with the !FeynRules generated ones (!CalcHep and !MadGraph) through the calculation of various 2 to 2 cross sections. For each implementation, we have fixed all the parameters to those of  [/attachment/wiki/NMSSM/valid.dat a specific benchmark point] and set the __widths of the particles to zero__. We have calculated 2 to 2 cross sections related to the production of any pair of particles from a Standard Model initial state of __2x1500 GeV__, in unitarity gauge. The results are available here [/attachment/wiki/NMSSM/validation.tgz validation.tgz].