OPUCEM - Oblique Parameters Using C with Error-checking Machinery

OPUCEM (pronounced ö-peu-gem, with o-umlaut as in French deux) is a C library which combines formulas from a multitude of references for calculating Peskin-Takeuchi parameters S-T-U. The aim is to provide a minimum-dependence code to facilitate the sharing of formulas, such that:

• Article authors can provide typo-free versions of their formulas that match their published numerical results.
• Cross-checks are done to compare formulas in different papers directly.
• Reviews by any interested party is possible.
• Further studies can refer to a certain version of the code and future errata can easily be done.

We aim to provide extra test functions in our library that does the cross-checking of different formulas - against approximation, against other calculations of the same quantities or against limiting cases of other quantities.

Currently implemented are:

• new lepton doublets with Dirac-or-Majorana-type neutral leptons
• new quark doublets
• SM and 2HDM Higgs boson
• recalculation of the SM origin in the S-T plane based on reference values of the masses of the top quark and the Higgs boson

References for the current code include:

• M.S. Chanowitz, Phys. Rev. D79 (2009) 113008
• H.-J. He, N. Polonsky, S. Su, Phys. Rev. D64 (2001) 053004
• J.R. Forshaw, D.A. Ross, B.E. White, JHEP0110:007 (2001)
• A.A. Natale, P.S. Rodriges Da Silva, Mod. Phys. Lett. A10 (1995) 1829
• B.A. Kniehl, H.-G. Kohrs, Phys. Rev. D48 (1993) 225
• E. Gates, J. Terning, Phys. Rev. Lett. 67 (1991) 1840

Example driver code to use the library, tools for plotting ST ellipses and (extensive) internal documentation are provided as well. The latest stable tag is opucem-00-00-04.

For a review of OPUCEM and an example of its application, see the talk given at the Second Workshop on Beyond 3 Generation Standard Model in Taipei. You might also have a look at our screenshots page.

Contacts