openloops is hosted by Hepforge, IPPP Durham




About The OpenLoops program is a fully automated implementation of the Open Loops algorithm for the fast numerical evaluation of tree and one-loop matrix elements for any Standard Model process.

On this website you find the latest version of OpenLoops with installation instructions and a documentation of the most important features, input parameters, and available Fortran90 and C/C++ interfaces.

This webpage is still under construction and will be updated regularly. A reference manual will become available soon.

Cite When OpenLoops is used for a publication please cite:

F. Cascioli, P. Maierhöfer and S. Pozzorini,
Phys. Rev. Lett. 108 (2012) 111601

as well as the third party tools used for one-loop reduction and scalar integrals.

Contact please send comments and bug reports to and subscribe to our mailing list to keep updated.