Version 21 (modified by 13 years ago) ( diff ) | ,
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The most general Minimal Supersymmetric Standard Model
Author
- IPHC Strasbourg / University of Strasbourg
- fuks@…
Description of the model & references
One popular Beyond the Standard Model theory is the Minimal Supersymmetric Standard Model (MSSM). Its main features are to link bosons with fermions and unify internal and external symmetries. Moreover, it allows for a stabilization of the gap between the Planck and the electroweak scale and for gauge coupling unification at high energies, provides a dark matter candidate as the lightest supersymmetric particle and appears naturally in string theories. However, since supersymmetric particles have not yet been discovered, supersymmetry must be broken at low energies, which makes the superpartners massive in comparison to their Standard Model counterparts.
Our MSSM implementation in FeynRules is the most general one in a 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. This yields thus 105 new free parameters. In order to deal in a transparent way with all of those, our implementation will follow the commonly used universal set of conventions provided by the Supersymmetry Les Houches Accord, except for some minor points (see instructions below).
The current version of the model, compatible with FeynRules v1.6.0 and below used the superspace module of FeynRules.
- Phys.Rept.110 (1984) 1: H. P. Nilles, Supersymmetry, Supergravity and Particle Physics.
- Phys.Rept.117 (1985) 75: H. E. Haber and G. L. Kane, The Search for Supersymmetry: Probing Physics Beyond the Standard Model.
- Phys.Rev.D41 (1990) 3464: J. Rosiek, Complete Set of Feynman Rules for the Minimal Supersymmetric Extension of the Standard Model.
- hep-ph/9709356: S. P. Martin, A Supersymmetry primer.
- JHEP 0407 (2004) 36: P. Skands et al, SUSY Les Houches accord: Interfacing SUSY spectrum calculators, decay packages, and event generators .
- Comput.Phys.Commun.180 (2009) 8: B. C. Allanach et al, SUSY Les Houches Accord 2.
Model files
- mssm.fr: MSSM implementation using the superspace module (compatible with FeynRules 1.6.x)
- sps1a: parameter file to be read, associated to the sps1a scenario.
- MSSM.nb: Example of a Mathematica® notebook loading the model and the parameters.
- susy1.0.1.tgz (05.07.09): Old MSSM implementation (compatible with FeynRules 1.4.x), with the corresponding parameter file for the sps1a benchmark point, and the old example notebook.
Sepcific 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)
sps1a_ch.tgz | The model files for CalcHep. |
sps1a_fa.tgz | The model files for FeynArts. |
sps1a_mg.tgz | The model files for MadGraph 4. |
Not supported | The model files for Sherpa. |
sps1a_ufo.tgz | The model files in UFO format (e.g. for MadGraph 5). |
sps1a_wo.tgz | The model files for Whizard. |
Validation
In order to validate our implementation, we have performed the following tests.
- FeynArts model file generated by FeynRules: recalculation of the helicity amplitudes related to the hadroproduction of a pair of supersymmetric particles and comparison with the three references:
- Nucl. Phys. B787 (2007) 1: G. Bozzi, B. Fuks, B. Herrmann and M. Klasen, Squark and gaugino hadroproduction and decays in non-minimal flavour violating supersymmetry.
- Nucl. Phys. B810 (2009) 266: B. Fuks, B. Herrmann and M. Klasen, Flavour Violation in Gauge-Mediated Supersymmetry Breaking Models: Experimental Constraints and Phenomenology at the LHC.
- B. Fuks , private communication.
- Comparison of the built-in CalcHEP (CH-ST) and MadGraph (MG-ST) model files with the FeynRules generated ones, MG-FR and CH-FR, through the calculation of various quantities. For each implementation, we have fixed all the parameters to those of SPS 1a and set the widths of the particles to zero.
- 1 to 2 decay widths for all Standard Model particles and their superpartners (320 channels), for MG-FR and MG-ST: decay.tgz.
- 2 to 2 cross sections related to the production of any pair of particles from a Standard Model initial state of 2x600 GeV and 2x1000 GeV, and for the four implementations CH-ST, CH-FR, MG-ST and MG-FR. CalcHEP is run in unitary gauge.
- 2 to 3 matrix element evaluation for given phase space points: not available yet.
- Note: we have some disagreements (red spots in the jpg-files). They are due to
- A certain amount of bugs in the CH-ST implementation.
- Massless propagators in t-channel diagrams leading to unreliable results for all implementations. We have tested here unintegrated matrix elements for 100 different phase space points: sa.tgz.
Attachments (15)
-
susy1.0.1.tgz
(12.8 KB
) - added by 15 years ago.
FeynRules MSSM model files
-
SUSY.nb
(9.1 KB
) - added by 15 years ago.
Example notebook
-
FRT_paramcard.dat
(18.8 KB
) - added by 15 years ago.
SPS1a paramcard
-
sps1a_mg.tgz
(61.3 KB
) - added by 13 years ago.
MadGraph model files for sps1a
-
validation.tgz
(1.9 MB
) - added by 13 years ago.
Validation tables for sps1a
-
sps1a_tex.tgz
(11.5 KB
) - added by 13 years ago.
Output of the TeX interface
-
sps1a_fa.tgz
(23.7 KB
) - added by 13 years ago.
FeynArts model files for sps1a
-
sps1a_wo.dat
(20.8 KB
) - added by 13 years ago.
ParamCard for MSSM-SF compatible with Whizard
-
MSSM.nb
(13.0 KB
) - added by 13 years ago.
Example notebook
-
sps1a_wo.tgz
(236.3 KB
) - added by 13 years ago.
Whizard model files for sps1a
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sps1a.dat
(20.8 KB
) - added by 13 years ago.
Param_card for the sps1a point
-
mssm.fr
(45.5 KB
) - added by 12 years ago.
MSSM model file v 1.3.13
-
sps1a_ufo.tgz
(61.1 KB
) - added by 11 years ago.
UFO files for the MSSM
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sps1a_ch.tgz
(51.6 KB
) - added by 11 years ago.
CalcHep model files for sps1a
- translator2.2.tgz (33.5 KB ) - added by 10 years ago.