SPheno

SPheno stands for S(upersymmetric) Pheno(menology).

The code calculates the SUSY spectrum using low energy data and a user supplied high scale model as input. The spectrum is then used for calculating the following:

• Two- and three-body decay modes of supersymmetric particle as well as of Higgs bosons;
• The production cross sections for supersymmetric particle and Higgs bosons in e^+ e^- annihilation;
• The branching of the decay $b \to s \gamma$
• Contributions to anomalous magnetic moment of the muon;
• Contributions to the $\rho$ parameter due to sfermions.

The code is written in F90 with an emphasis on easy generalisability. The structure is set such that complex phases as well as the extension to include the flavour structure can be done in a straight forward way. The 2-loop renormalization group equations as well as the one-loop finite corrections a la Bagger, Matchev, Pierce and Zhang are included. In addition the two-loop corrections to the neutral Higgs boson masses (a la Brignole, Degrassi, Slavich and Zwirner) and to the mu-parameter (a la Dedes and Slavich) are included. Starting with version 2.2.2 the SUSY Les Houches Accord is supported as well as the SPA conventions (for details see hep-ph/0511344).

Starting with version 3.0 the complete flavour and CP structure of the MSSM as well as bilinear R-parity violation has been implemented. The input and output is done via he SUSY Les Houches Accord 2 . Moreover, starting with version 3.1.10 also parts of the proposal to include seesaw models has been implemented, see the corresponding chapter of the Les Houches Proceedings 2011 and with version 3.1.10 also parts of the Flavour Les Houches Accord have been implemented.

If you use SPheno to write a paper, please cite the SPheno manuals:

• W. Porod, Comput. Phys. Commun. 153 (2003) 275 arXiv:hep-ph/0301101; and
• W. Porod and F. Staub, Comput. Phys. Commun. 183 (2012) 2458 arXiv:1104.1573

More information is provided in the manuals in the doc/ folder.

In case of problems, please send an email to porod@physik.uni-wuerzburg.de explaining the problem. Useful informations is in general contained in the file Messages.out; moreover, you should provide me with the input files used so that I can try to repeat the run and to decect the source of the problem.

Installation

SPheno can be download from Hepforge. After download and extracting the archive, it can be compiled with:

mkdir build
cd build
cmake ..
make
make install

By default, make install installs the library and binary into the same directory as the source; however, this can be customized by adding -DCMAKE_INSTALL_PREFIX=/foo/bar to the cmake command.

SARAH Models

For models generated by SARAH (or by other means), the SPheno output should be copied into a new directory inside models/ that has the same name as your main model. For example, if the model name is SM, then running MakeSPheno[] in Mathematica will create

$SARAH_OUTPUT/SM/EWSB/SPheno

and the contents of that folder should then be copied into models/SM. The model-specific SPheno executable and library can now be generated by running the same steps as above, but adding -DMODELS=SM to the cmake command. Multiple models can be specified by separating them with commas: -DMODELS=SM,MSSM,THDM-II.

As an example, here's the whole procedure for the SM model:

mkdir models/SM
cp $SARAH_OUTPUT/$MODEL/EWSB/SPheno/. models/SM
mkdir build
cd build
cmake -DMODELS=SM
make
make install

Note that if your file system supports it, you can create a symbolic link in the models/ directory linking to $SARAH_OUTPUT/$MODEL/EWSB/SPheno. This has the advantage that if you change the model in SARAH, you don't need to copy them over to SPheno again. The whole procedure is:

ln -s $SARAH_OUTPUT/$MODEL/EWSB/SPheno models/$MODEL
mkdir build
cd build
cmake -DMODELS=$MODEL
make
make install

Running

To run SPheno, it simply needs to be given an input file:

./bin/SPheno input/LesHouches.in

This will generate two files:

• SPheno.spc: contains all information about masses, mixing matrices, decay widths, branching ratios and production cross sections. The numbers should be identical to the ones given in the file SPheno.spc.mSugra provided you did not change the file LesHouches.in;
• Messages.out containing warnings and error messages.

Some example LesHouches files are provided in the input/ directory.

Package Content

The package consists of the following files fortran 90 modules:

• SPheno3.f90: main program containing also the input/output routines
• BranchingRatios.f90: module for the calculation of the decay widths and branching ratios of SUSY particles and Higgs bosons
• Chargino3.f90: module, containing routines for the calculation of three-body decays of charginos
• Control.f90: module containing routines for warning and error handling
• Couplings.f90: module, containing routines for the calculation of the couplings
• DecayFunctions.f90: module, containing generic routines for the calculation of two-body decays
• EplusEminusProduction.f90: module, containing routines for the calculation of the production cross sections in e+ e- annihilation
• Gluino3.f90: module, containing routines for the calculation of three-body decays of the gluino
• InputOutput.f90: module, containing routines for input and output
• LHC_observables.f90: module, containing routines for LHC observables, e.g. edge variables
• LoopCouplings.f90: module, containing routines for the calculation of the running couplings
• LoopFunctions.f90: module, contining 1-loop and 2-loop functions
• LoopMasses.f90: module, containing the routines for the calculation of the loop masses
• LowEnergy.f90: module, containing routines for the calculation of low energy observables
• Mathematics.f90: module, containing numerical routines
• MathematicsQP.f90: module, containing numerical routines with quadrupole precision
• Model_data.f90: module containing variables concerning SUSY parameters, masses, decay widths and branching ratios
• Neutralino3.f90: module, containing routines for the calculation of three-body decays of neutralinos
• NMSSM_tools.f90: module, containing first modules for the NMSSM
• RGEs.f90: module, containing the RGEs
• RPtools.f90: module, containing additional modules for R-parity violation
• Slepton3Body.f90: module, containing routines for the calculation of three-body decays of sleptons
• SPheno3.f90: The main program for the package.
• StandardModel.f90: module, storing the Standard Model parameters
• Stop3BodyDecays.f90: module, containing routines for the calculation of three-body decays of the lighter stop
• SugraRuns.f90: module, containing the routines for setting the boundary conditions, controlling the running of the parameters as well as calculating the spectrum in case of high scale models
• SusyDecays.f90: module, containing routines for the calculation of all two-body decays of supersymmetric particles and Higgs bosons
• SusyMasses.f90: module, containing the routines for the calculation of supersymmetric masses at tree level
• ThreeBodyPhaseSpace.f90: module, containing routines for the calculation of the phase space integrals for three-body decays of fermions
• ThreeBodyPhaseSpaceS.f90: module, containing routines for the calculation of the phase space integrals for three-body decays of scalars
• TwoLoopHiggsMass.f90: module, containing the 2-loop routines for the calculation of neutral Higgs boson masses and mu

In addition the following set of input files are provided:

• LesHouches.in: mSUGRA input file (same as LesHouches.in.mSugra)
• LesHouches.in.mSUGRA_NUHM: mSUGRA input file but with non-universal Higgs mass parameters
• LesHouches.in.AMSB: AMSB input file
• LesHouches.in.GMSB: GMSB input file
• LesHouches.in.mNUHM: mSUGRA scenario but fixing Higgs sector at the electroweak scale using the pole mass of the pseudoscalar Higgs boson and the mu parameters
• LesHouches.in.SeesawI: example of an mSUGRA scenario combined with seesaw type I
• LesHouches.in.SeesawII: example of an mSUGRA scenario combined with seesaw type II, requires the compilation with option -DSEESAWIII
• LesHouches.in.SeesawIII: example of an mSUGRA scenario combined with seesaw type III, requires the compilation with option -DSEESAWIII

The package includes also sample output data corresponding to the input files specified above, denoted by SPheno.out.xyz and SPheno.spc.xyz, where xyz stands for any of the models above in the directory input/.