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Change Log

  • 30th Jul 2019: OpenLoops 2.1.0 released.
    • Version matches the OpenLoops 2 publication.
    • Significant stability improvements thanks to improved hyprid precision system.
    • Special treatment of on/off-shell photons.
    • Mixed on-shell/complex-mass-scheme renormalisation at NLO EW..
    • Various improvements and bug-fixes.
  • 8th Mar 2019: OpenLoops 2.0.0 released.
    • Significant speed and stability improvements thanks to in-house on-the-fly integral reduction and hyprid precision system.
    • Note: preset and stability settings of OpenLoops 1 become deprecated.
    • Support of NLO QCD and NLO EW corrections in the full SM.
    • Default EW input scheme: Gmu. Mixed scheme for external photons.
    • Various improvements and bug-fixes.
  • 27th Apr 2016: OpenLoops 1.3.1 released.
    • Bugfix in R2 rational terms. Versions prior to 1.3.0 not affected.
  • 25th Apr 2016: OpenLoops 1.3.0 released.
    • Includes the COLLIER (collier-1.0) tensor integral reduction library. Specifying the parameter preset=2 uses COLLIER via the stability mode 23.
    • Non-diagonal CKM matrix. Has to be supported by the process library.
    • New interface subroutine tree_colourflow(id,basis) to retrieve the colour basis in colour flow representation. Basis has the shape basis(2,nex,ncolb), where ncolb is the number of basis elements and nex is the number of external particles.
    • Bugfix in qp rescue system for loop-squared processes.
    • Bugfix in spin-correlated born amplitudes. Only effects 2->1 processes.
    • Various improvements and bug-fixes.
  • 25th Jan 2016: OpenLoops 1.2.4 released.
    • new parameter: check_collection=0 disables the check of the online collection
    • Various minor improvements and bug-fixes.
  • 1st Oct 2015: OpenLoops 1.2.3 released.
    • Bugfix in the parameter initialisation of the quad precision rescue system. Versions prior to 1.2.2 not affected.
  • 25 Sep 2015: OpenLoops 1.2.2 released.
    • Upgrade in the library loader: OpenLoops does not write temporary files anymore.
    • Changed defaults: stability log files are not written by default, i.e. stability_log=0.
    • Possibility to set the cc, cxx, and cpp commands in the openloops.cfg file.
    • Improved platform compatibility.
    • Bugfix for particle decays.
    • Various improvements and bug-fixes.
  • 6 Aug 2015: OpenLoops 1.2.1 released.
    • Fix in build system.
    • Bugfix in flavour mapping when yukawas /= masses.
  • 21 Jul 2015: OpenLoops 1.2.0 released.
    • Update is strongly recommended if OpenLoops is used with Sherpa 2.2 (or later) or Herwig++.
    • Added support for Yukawa couplings which are differ from fermion masses (requires support in the process library).
    • Regularization- (mureg) and renormalization scale (muren) can be set independently.
    • Various improvements and in the process loader, including bugfixes (mostly in corner cases).
    • Improved log and error messages.
    • Upgraded OneLOop to version from 10 May 2015, based on OneLOop 3.6.
    • New Python bindings and test script (./openloops run).
  • 23 Apr 2015: OpenLoops 1.1.1 released.
    • Yukawa renormalisation scale as free parameter muy(PDG). Warning: feature has to be supported by the corresponding process library and Sherpa <= 2.1 does not automatically initialise Yukawas in OpenLoops.
    • Minor improvements and bug-fixes.
  • 25 Mar 2015: OpenLoops 1.1.0 released.
    • Download and installation of new/updated libraries via
      ./openloops libinstall <lib1> [<lib2> [...]]
    • Update of OpenLoops (only if installed from SVN) and all installed processes with a single command:
      ./openloops update
      Or process update only (if OpenLoops was installed from tarball): ./openloops update --processes
    • Remove an installed process: ./openloops rm .
    • Full matrix of colour-correlated tree amplitudes can be obtained via evaluate_ccmatrix interface.
    • Improved library loader.
      - Performance improvements, especially when many processes are loaded.
      - Preference to take tree libraries from already loaded loop libraries. I.e. by convention loop processes should be loaded before tree (real) processes.
      - More detailed messages in case of missing/incompatible processes or in verbose mode.
      - Fixed a bug which lead to wrong crossing initialisation in very rare cases.
    • Support to include real correction matrix elements in loop libraries (new libraries will be available within April 2015). Monte Carlos (Sherpa in particular) might use their own tree matrix elements. Compilation of real corrections can be deactivated with compile_extra=0 in openloops.cfg.
    • Support for Higgs effective theory (HEFT).
    • Introduced routines to retrieve tree amplitudes with full colour information.
    • Yukawa couplings can in general be different from mass parameters. They have to be set after the mass parameters as yuk(PID). Warning: feature has to be supported by the corresponding process library and Sherpa <= 2.1 does not automatically initialise Yukawas in OpenLoops.
    • Support for amplitudes with (in principle) arbitrarily high tensor rank.
    • Fixed a possible string overflow in the parameter initialisation.
    • Simple mechanism to modify compiler options, e.g. optimisation and support for 64-bit addressing.
    • Bugfix in the Rambo interface on MacOS X.
    • Various minor improvements and bug-fixes.
  • 24 Okt 2014: OpenLoops 1.0.1 released.
    • Various improvements and bug-fixes in the channel mapping (does not affect Sherpa users). Requires process update.
    • Bugfix in couterterm routine (internal renormalisation was not affected, only dedicated evaluate_ct calls).
    • Process look-up: when a process is not installed, but the library exists in the repository, the user is notified. The information which processes are available is stored locally and updated when any process is updated.
    • If a process was registered before, the existing id is returned.
  • 2 Sep 2014: OpenLoops 1.0.0 released.