SoftSUSY is hosted by Hepforge, IPPP Durham


by: B C Allanach, P Athron, A Bednyakov, M Bernhardt, T Cridge, D Grellscheid, M Hanussek, C H Kom, S Martin, D Robertson, R Ruiz de Austri, P Slavich, L Tunstall, A Voigt and A G Williams

[download | technical documentation | previous releases ]
manuals [main | decays | NMSSM | RPV | RPV nu | 2 loop gauge/Yukawa | 2 loop squark/gluino]


This program provides a SUSY spectrum in the NMSSM, or the MSSM including flavour violation and with or without R-parity consistent with input Standard Model fermion mass/mixings and electroweak/strong coupling data. The R-parity violating mode can calculate neutrino masses and mixings to 1 loop. SOFTSUSY can be used in conjunction with other programs for many different particle physics calculations: see a SUSY tools review. See graphs of [ gauge unification | (zoom) | MSSM RGE evolution ] (feel free to use them). SOFTSUSY now has a mode with 3 loop RGEs and some 2-loop threshold correction and 2-loop SUSY QCD corrections to gluino and squark pole masses. SOFTSUSY now computes decay branching ratios for the MSSM and NMSSM.

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If you use SOFTSUSY to write a paper, please cite (see MCnet guidelines)

[1] B.C. Allanach, Comput. Phys. Commun. 143 (2002) 305-331, hep-ph/0104145,

which is the SOFTSUSY manual for the R-parity conserving MSSM.
If you use the decay calculations, please cite [1] and

[1b] B.C. Allanach and T. Cridge, arxiv:1703.09717

If you calculate in the NMSSM, please cite [1] and

[2] B.C. Allanach, P. Athron, L. Tunstall, A. Voigt and A. Williams, Comput. Phys. Comm. 185 (2014) 2322, arXiv:1311.7659.

If you use the R-parity violating aspects, please cite [1] and

[3] B.C. Allanach and M.A. Bernhardt, Comput. Phys. Commun. 181 (2010) 232, arXiv:0903.1805.

If you use it to calculate neutrino masses and mixings, please cite [1], [3] and

[4] B.C. Allanach, M. Hanussek and C.H. Kom, Comput. Phys. Commun. 183 (2012) 785, arXiv:1109.3735.

If you use the three-loop RGEs or two-loop threshold corrections to gauge/Yukawa couplings, please cite [1] and

[5] B.C. Allanach, A. Bednyakov and R. Ruiz de Austri, Comput. Phys. Commun. (2015) 192, arXiv:1407.6130.

If you use the two-loop SUSY QCD corrections to squark and gluino pole masses, please cite [1] and

[6] B.C. Allanach, Stephen P. Martin, David G. Robertson and Roberto Ruiz de Austri, arXiv:1601.06657.

These reference are collected here in a bibTeX file for handy inclusion into latex documents.


For ultra-basic instructions, see the introduction video. Otherwise, see a quick tutorial given at BUSSTEPP 2012.

To run SOFTSUSY, you should need only standard C++ and fortran libraries.

The following releases contain a test program (main.cpp) and the SOFTSUSY library (libsoft.a, link with -L.libs -lsoft). In linux, just unpack the files with (eg for softsusy-4.0)

> gunzip softsusy-4.0.tar.gz
> tar -xvf softsusy-4.0.tar 
> cd softsusy-4.0
To compile the code
> ./configure 
> make 
There are six test programs, which can be run by the commands
> ./softsusy.x > inOutFiles/outputTest
> ./rpvsoftsusy.x > inOutFiles/rpvOutputTest
> ./rpvneut.x > inOutFiles/neutOutputTest
> ./softsusy-nmssm.x > inOutFiles/outputTest-nmssm
> ./higher.x
> ./softpoint.x
This last executable requires additional command line options. For instance, you can run the SUSY Les Houches Accord input provided by running the commands
> ./softpoint.x leshouches < inOutFiles/lesHouchesInput > inOutFiles/lesHouchesOutput
> ./softpoint.x leshouches < inOutFiles/nmssmSLHAnoZ3Input > inOutFiles/nmssmSLHAnoZ3Output
> ./softpoint.x leshouches < inOutFiles/nmssmSLHAZ3Input > inOutFiles/nmssmSLHAZ3Output
> ./softpoint.x leshouches < inOutFiles/rpvHouchesInput > inOutFiles/rpvHouchesOutput
> ./softpoint.x leshouches < inOutFiles/slha2Input > inOutFiles/slha2Output
All of the output files mentioned above are produced by the Makefile automatically.
SOFTSUSY executables use no input or output files except from standard input or standard output.

Note that the executables are actually wrapper scripts, the "true" executables lie in the directory .libs/ (from the directory where you installed softsusy).

If you have trouble with compilation, try this page.

Particle Decays

An example point including the calculation of sparticle decays, neglecting modes with a branching ratio of less than 1.0e-5, and outputting the partial widths in the comments:
./softpoint.x gmsb --n5=2 --mMess=1.0e6 --LAMBDA=5.0e5 --tanBeta=10 --sgnMu=1 --decays --minBR=1.0e-5 --outputPartialWidths

High Orders Mode

If the 2-loop SUSY QCD corrections to squark and gluino masses are required, do
> ./configure --enable-two-loop-sparticle-mass-compilation
> make 
An example point using the higher order terms can be run with, for example,
> ./softpoint.x sugra --tol=1.0e-4 --m0=1000 --m12=1000 --a0=0 --tanBeta=10 --sgnMu=1 --two-loop-sparticle-masses --two-loop-sparticle-mass-method=1

High Accuracy Mode

If the high accuracy mode with 3-loop RGEs and some 2-loop threshold corrections is required, first install CLN and GiNaC, then
> ./configure --enable-two-loop-gauge-yukawa-compilation --enable-three-loop-rge-compilation
> make 
An example point using the high accuracy mode can be run with, for example,
> ./softpoint.x sugra --tol=1.0e-5 --m0=7240 --m12=800 --a0=-6000 --tanBeta=50 --sgnMu=1 --mt=173.2 --alpha_s=0.1187 --mbmb=4.18 --two-loop-susy-thresholds --three-loop-rges
See [5] for more details.

Executable files: after installation

SOFTSUSY-specific input for SUSY Les Houches Accord input files

Block SOFTSUSY           # SOFTSUSY specific inputs
  0   <calcDecays>       # Set to 1 to calculate decays/0 (default) for no decays
  1   <TOLERANCE>        # desired fractional accuracy in output
  2   <MIXING>           # quark mixing option
  3   <PRINTOUT>         # gives additional verbose output during calculation
  4   <QEWSB>            # change electroweak symmetry breaking scale
  5   <INCLUDE_2_LOOP_SCALAR_CORRECTIONS>    # Full 2-loop running in RGEs
  6   <PRECISION>        # number of significant figures in SLHA output
  7   <numHiggsLoops>    # number of loops in REWSB/mh calculation
  8   <susyRpvBCatMSUSY> # Switch MSUSY-scale RPV boundary conditions ON
  9   <invertedOutput>   # RPV neutrino output uses normal hierarchy (=0.0) or inverted (=1.0)
 10   <forceSlha1>       # if =1, tries to force output into SLHA *1* format
 11   <m32>              # sets gravitino mass to m32
 12   <printSpectra>     # Prints spectrum even when point is theoretically excluded if=1
 13   <mAFlag>           # If=0 (default), sets tachyonic mA=0, otherwise mA=sqrt(|mA|^2)
 15   <NMSSMTools>       # If=1, enables NMSSMTools compatible SLHA2 output
 16   <MICROMEGAS>       # Micromegas options for NMSSMTools use: 1=RD, 2=DD, 3=ID, 4=both
 17   <NMSDECAY>         # If=1, flags for sparticle decays to be calculated via NMSDECAY
 18   <SoftHiggsOut>     # If=1, then the EWSB conditions output soft Higgs masses in NMSSM
# 19 Only works with ./configure --enable-three-loop-rge-compilation 
 19   <threeLoopRGEs>    # If=1, then 3-loop MSSM RGEs included (default of 0 to disable)
# 20 Only works with ./configure --enable-two-loop-gauge-yukawa-compilation 
 20   <gyThresholds>     # If>0, switch on gauge/Yukawa two-loop thresholds (see manual [5] for details). 
                           If=31, they all are switched on (default 0 to disable).
# 22,23 only work with --enable-two-loop-sparticle-mass-compilation
 22    <2-loop squark/gluino>   # Include 2-loop terms in gluino/squark masses (1 for on, 0 for off)
 23    <expandAroundGluinoPole> # sets expandAroundGluinoPole parameter (default 3)
 24    <minBR>                  # If decay BR is below this number, don't output
 25    <threeBodyDecays>        # If set to 0, don't calculate 3-body decays (1=default)
 26    <outputPartialWidths>    # If set to 1, output partial widths (0=default)

Source Files

Contained in the gzipped tarred archive above, but the details of some of them are listed here:

Input, output and information files

These input and output files are contained in the inOutFiles/ subdirectory:


The source code is contained in the src/ subdirectory.

Comparisons With Other SUSY Spectrum Generators

There are detailed comparisons between SOFTSUSY and other R-parity conserving MSSM publicly available programs in and comparisons with NMSSM generators in



    SOFTSUSY Copyright (C) 2007 B.C. Allanach

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    GNU General Public License for more details.