A code for the calculation of loops diagrams in the MSSM
with application to collider physics, astrophysics and cosmology
N. Baro, F. Boudjema, A. Semenov and A. Temes
- First of all, although quite a few elements have been implemented, the code is not complete yet. So bear with us.
- Some application of the code has been published here. A more detailed description is given here.
- The principle behind the code is modularity. Considering the complex structure of the MSSM (large number of parameters) and that no simple complete renormalisation scheme of the MSSM has emerged one should have a code that is flexible enough so that it simple to define the model file. Moreover since different codes exist already that deal with important ingredients in the calculation of loops it is best to exploit these, combine them together and whenever improve on them.
- Model definition both at tree-level and at one-loop level is done with LANHEP adapted such that it can be interfaced with the FeynCalc/FormCalc package.
- Model file:
- example of particle definition, gauge fixing and ghost Lagrangian via BRS in LANHEP.
- Feynman rules including counterterms (see here).
- renormalisation conditions (see here).
- A poweful feature of the code is the use of a non-linear gauge fixing condition (see here) .
- The aim of the code is also to be used for annihilation of dark matter that is highly non relativistic, this calls for an added routine in the loop tensor reduction that avoids Gram determinants. Our trick is to do this and this .
- Overview of strategy (here)
- Example of combining SloopS with micrOMEGAs to predict the photon flux from neutralino annihilation (Thanks to Pierre Brun).
