QGRAF's Webpage


News

QGRAF-3.3 is available (July 2018).

QGRAF-R has been updated (June 2018).

qgraf

qgraf is a computer program that can generate Feynman diagrams and represent them by symbolic expressions; no graphical representation is generated, though. It was written to assist in large perturbative calculations, in the context of Quantum Field Theory.

  • Programming language: FORTRAN 77 (there should be some evolution in the next major release).
    Binaries/executables are not distributed; the program has to be compiled and linked, eg with gfortran.

  • Latest release: version 3.3 (July 2018).
    The features added since the release of version 3.1.4 include:
    increased performance in some ‘extreme’ cases (3.1.5);
    option “onshellx”, an extended form of “onshell” (3.2);
    a way of restricting the configuration of external lines (3.3);
    the ability to require/disallow bridge-type propagators with certain momenta (3.3);
    improved treatment of duplicate vertices (3.3).

  • A note to software developers: version 3.4, which should be available before the end of 2018, will be the next ‘stable’ version (ie available for a long period, minimal fixes if need be).

  • Please report any error you may happen to find; the known problems are listed here.

  • The algorithm used to generate the diagrams is described (in its basic form) in the following article:

    • Automatic Feynman graph generation
      P. Nogueira
      J. Comput. Phys. 105 (1993) 279-289
      https://doi.org/
      10.1006/jcph.1993.1074

qgraf-r

qgraf-r is a computer program that can find (particle) number conservation rules for particle physics models — both “additive” and “multiplicative” rules. It can then identify (un)physical processes that break those rules, thereby establishing the non-existence of matching Feynman diagrams to all orders of perturbation theory.

qgraf-r may also be used in the cross-checking of model-files accepted by qgraf: if the rules found by qgraf-r are not as expected then the model description is likely wrong.

  • Programming language: FORTRAN 77.
    No binaries either, the program should be compiled with eg gfortran.

  • Latest release: version 0.6 (June 2018).

  • Please report any error you may happen to find; the known problems are listed here.

  • Some of the theory behind qgraf-r is described in these papers:

    • From Feynman rules to conserved quantum numbers, I
      P. Nogueira
      Comput. Phys. Commun. 214 (2017) 83-90
      https://doi.org/
      10.1016/j.cpc.2017.01.025

    • From Feynman rules to conserved quantum numbers, II
      P. Nogueira
      Comput. Phys. Commun. 215 (2017) 13-19
      https://doi.org/
      10.1016/j.cpc.2017.01.027

downloads

A login window should appear upon clicking one of the links displayed below; then enter anonymous as username and (optionally) as password too.
NB: accesses are logged; the username should be entered correctly, access will be denied if there is any typo or even some white space.

The following links let you pick either a tgz type archive or the individual files. There are two (incompatible) major releases to choose from; release 3 is recommended unless, for compatibility reasons, release 2 is really required. The known problems are listed here.

  • compressed archives ( tar + gzip )

    • qgraf-3.3.tgz
      size
      340K
      sha256sum
      09306d98466321014fa95053d5aff61060c62ebd9145803e92c5abcb701bc268
      qgraf-3.1.4.tgz
      size
      279K
      sha256sum
      b6f827a654124b368ea17cd391a78a49cda70e192e1c1c22e8e83142b07809dd
      qgraf-2.0.tgz
      size
      125K
      sha256sum
      0e3545cbb4171499f668d2dd03db05ddaf2b133468984fb7693facc33261c813
  • uncompressed files

There is also a tool (designed for Linux/Gnu and compatible systems) to convert model-files and style-files written for version 2.0 into files suitable for versions 3.x.

    • q2to3.tgz
      size
      60K
      sha256sum
      3a08c60cf7addd212570df4baea472b8194144b8d5e29dfb031549f92adbfe87

For now qgraf-r should be treated as a beta-release; it seems to work, though.

    • qgraf-r.tgz
      size
      88K
      sha256sum
      fe2d04cd6f83b0dac1ed3fd885805ed9e2f83bcf388c354e3d8a50117ca53b87
some links to other computer programs


Further links may be found on this web page or this other web page.

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