blackmax is hosted by Hepforge, IPPP Durham


BlackMax is a comprehensive black-hole event generator, which simulates the experimental signature of microscopic and Planckian black-hole production and evolution at the LHC in the context of brane-world models with low-scale quantum gravity. The generator is based on phenomenologically realistic models free of serious problems that plague low-scale gravity, thus offering more realistic predictions for hadron-hadron colliders. The generator includes all of the black-hole gray-body factors known to date and incorporates the effects of black-hole rotation, splitting between the fermions, non-zero brane tension and black-hole recoil due to Hawking radiation (although not all simultaneously)

BlackMax simulates only the production and decay of the black holes. It has been interfaced, via the Les Houches accord, to HERWIG and PYTHIA to perform the parton-shower evolution and hadronization of the partons produced in the decay. This is achieved either by directly calling the hadronisation event generators during event simulation, or by producing stand-alone BlackMax output in the Les Houches accord output text file format which can be used as input to Pythia / Herwig.

To be kept informed of new developments and updates please join the BlackMax mailing list:

Latest Version

  • Version 2.02.0 gzipped tar-file (14/01/11)
    • This is a bugfix release: In the two-particle model an asymmetry in the rapidity of decay particles was fixed.
  • Version 2.01.3 gzipped tar-file (18/03/10)
    • BlackMax has changed the way energy-momentum conservation is presented in events. Previously energy-momentum was conserved in all extra dimensions, but in the BlackMaxLHArecord.lhe file only 4-momenta are provided. The momentum in extra dimensions was set to zero and the particle energy altered to compensate for this whilst keeping the mass constant. Thus particles in extra dimensions have a different energy in BlackMaxLHArecord.lhe and in output.txt. This leads to the problem of apparent violation of energy-momentum conservation in 4d spacetime and could lead to problems in hadronisation models. In this version of BlackMax any apparent missing energy is compensated for by introducing an additional graviton in the 4d picture of the event only (BlackMaxLHArecord.lhe). There is no change to the full dimensional event information given in output.txt.
    • Note: in some rare cases energy-momentum is not conserved even in the full event information. This can occur when the decaying black hole recoils against emission and reaches a boundary in one of the brane dimensions. In this case the black hole momentum is reversed.
    • Bugfix: particles emitted in the final burst phase are now chosen without a mass preference. Previously particles with larger masses were preferentially chosen and this bug is now fixed.
    • Bugfix: in mode with event generation and simultaneous Pythia hadronisation, the initial Pythia setting was wrong so that BlackMax events were being overwritten by Pythia. This bug did not affect the production of the BlackMaxLHArecord.lhe file for input to hadronisation code later.
    • Bugfix: cross section written to BlackMaxLHArecord.lhe was garbled, but OK elsewhere. Cross sections in units of barns are now given in pb.
    • If hadronisation is required without B or B-L conservation an error message is generated and BlackMax quits.
  • Version 2.01.1 gzipped tar-file (10/11/09)
    • Stringball calculations are now included in a limited set of models (e.g. without Yoshino suppression, or no brane tension)
    • New parameters added allowing user to set the widths of the branes
    • Implementation of a faster method to calculate cross sections
    • User can now choose between cross sections calc'd using BH mass or partonic CMS
    • Improvement in the calculation of the quantum BHs
    • 2-body final state model is not compatible with split fermion model, this is now turned off
    • Bugfix in 2-body final state model
    • Bugfix in gluon contribution to cross sections
    • Bugfix in implementation of Pythia hadronisation

  • Version 2.00.3 gzipped tar-file (25/03/09)
    Minor modification to the output for full LHA compliance.
    • LHA output file renamed as BlackMaxLHArecord.lhe
    • additional XML tag added in LHA file header section
    • for standalone BlackMax PDF ID is correctly filled with CTEQ6.1M default set

  • Version 2.00.2 gzipped tar-file (23/02/09)
    • This is a minor bugfix with respect to release 2.00 affecting counting the colour degrees of freedom in the two-particle model only.

The BlackMax Manual for version 2.0 is available here or from the archive as


To install the programme:

  • download the tar-file of the version you want,
  • unzip and expand with tar -xvzf blackmax.tar,
  • move to the created blackmax directory,
  • read the README file in it for installation instructions.


If you use our generator please reference: Dai et al., "BlackMax: A black-hole event generator with rotation, recoil, split branes and brane tension.",
arXiv:0711.3012 [hep-ph], Physical Review D (Vol.77, No.7)