sarah is hosted by Hepforge, IPPP Durham

FlavorKit / PreSARAH

(by W. Porod, F. Staub, A. Vicente)

Current version

The current version of PreSARAH is 1.0.2 (Download)
FlavorKit included in SARAH since version 4.2.0 (SARAH)
Last change: 16.03.2015


The FlavorKit functionality is an extension of SARAH that increases the capability to handle flavor observables. The basic idea is that all information to calculate Wilson coefficients and to combine them into observables are provided by external files. These files can be edited/extended by the user and all changes are included in the SPheno output of SARAH. Therefore, it is possible for the user to extend easily the list of flavor observables calculated by the combination SARAH/SPheno.
To add also new operators we provide the Mathematica package PreSARAH which makes use of FeynArts/FormCalc to calculate the generic expressions for new Wilson coefficients, and to write all necessary input files for SARAH.


A detailed overview about the FlavorKit, the implemented operators and observables, and how to use PreSARAH is given in


  • 16.March 2015 (PreSARAH 1.0.3): Changed normalization for tree-level part for 4-fermion operators to get rid of factors 16pi^2; new function C0B0check to stabilize expressions involving B_0 + m C_0
  • 04.November 2014 (PreSARAH 1.0.2): Added to tree-level amplitudes also a factor 16pi^2 to have the same normalization for all amplitudes. Observable files in SARAH 4.4.0 adapted to the new convention!
  • 18.June 2014 (PreSARAH 1.0.1): Added input for l_i->l_j l_k l_k processes
  • 06.May 2014: FlavorKit released with SARAH 4.2.0; PreSARAH 1.0.0 public