Home of FeynHiggsFast

This code is no longer maintained (04.07.2005).
We strongly recommend to use the full (and also fast) version of FeynHiggs

FeynHiggsFast is a Fortran code for the fast and approximate diagrammatic calculation of the masses of the neutral CP-even Higgs bosons in the MSSM at the two-loop level.

The code is explained in hep-ph/0002213.
The calculation is based on hep-ph/9803277 and hep-ph/9807423 by S. Heinemeyer, W. Hollik and G. Weiglein.
See also hep-ph/9812472 for details.
Some of the approximations used in FeynHiggsFast are given in hep-ph/9903404.
For recent updates, see hep-ph/0212020.

In short: FeynHiggsFast contains the compact formula from the top/stop sector for the two-loop contribution to mh, the full one-loop corrections in the zero-momentum approximation and the resummation of QCD corrections from the bot/sbot sector involving gluinos and sbottoms.

You have now the same front-end as for the full version of FeynHiggs, including all the options (renormalizations scheme of input parameters, benchmark points etc.) Have a look at the Introduction of FeynHiggs!
The mass of the charged Higgs is calculated in the 1-loop approximation.

Download of the code:

This code is no longer maintained (04.07.2005).
We strongly recommend to use the full (and also fast) version of FeynHiggs

If you really insist on the old version, send an email to Sven Heinemeyer.

Last update: Dec. 04. 2003
What happened (FeynHiggsFast1.5.1):
A bug in the DRbar to OS transition (with iteration) for the sbottom sector has been removed (thanks to Jean-Loic Kneur and Pietro Slavich).
The perturbative diagonalization routine has been improved to cover also some more problematic cases (thanks go to Pietro Slavich).
The default value for the running b quark mass has been set to 2.74 GeV.

Oct. 27. 2003 (FeynHiggsFast1.5):
The transition from DRbar to on-shell for the stop and sbottom masses have been extended to include (besides the O(alphas corrections) also the O(alphat,b) corrections (thanks go to Pietro Slavich).

Jul. 17. 2003 (FeynHiggsFast1.4)
The version has been brought to the same level as FeynHiggs1.4. Exceptions: The O(alphab alphas), O(alphat alphab), O(alphab alphab) corrections are omitted, since they are quite longish and give only a small correction to the Higgs boson masses. On the other hand, for the O(alphat alphas), now the somewhat shorter formula derived in hep-ph/0105096 (G. Degrassi, P. Slavich, F. Zwirner) are used. Also the leading momentum dependent corrections are implemented as given in hep-ph/0112177 (A. Brignole, G. Degrassi, P. Slavich, F. Zwirner) (thanks go to Pietro Slavich).

Aug. 09. 2002 (FeynHiggsFast1.2.2):
A few more small Fortran bugs have been removed (Thanks go to Motoi Endo). Version should now also run with F90 compiler.

Aug. 01. 2002 (FeynHiggsFast1.2.1):
A few small Fortran bugs have been removed. Presetting of mu is now for positive values (200 or 1000 GeV).

Apr. 22. 2002 (FeynHiggsFast1.2):
The complete code has been reorganized. Now the full one-loop contribution at zero external momentum is evaluated. At the two-loop level the approximation for the O(alpha alphas) corrections as well as the O(alphat2) from hep-ph/0112177 (A. Brignole, G. Degrassi, P. Slavich, F. Zwirner) are incorporated.
tan beta enhanced two-loop QCD corrections have been implemented, following the effective Lagrangian approach given in hep-ph/9912516 (M. Carena, D. Garcia, U. Nierste, C. Wagner) have been implemented, including their resummation to all orders (thanks go to Ulrich Nierste!).

The SPS (Snowmass Points and Slopes, new benchmark points for SUSY searches) have been added as possible predefined input. For further information see the SPS home page or hep-ph/0202233, hep-ph/0201233.

The LH-BMS (Les Houches Benchmark Scenarios, new benchmark scenarios for MSSM Higgs boson searches at hadron colliders) have been added as possible predefined input. For further information see hep-ph/0202167 or the plots on the FeynHiggs main page.

Feb. 23. 2001
As in FeynHiggs, now also FeynHiggsFast provided the option to choose the renormalization scheme for the input parameters in the scalar quark sectior (On-Shell or MSbar) as described in hep-ph/0001002.

Mar. 06. 2000
A variable's declaration that had caused problems with some compilers has been changed. The number of continuation lines, which had been too large for some compilers, has been reduced.

Sep. 06. 1999
The calculation of the mixing angle alpha in the neutral CP-even Higgs sector is performed at tree level, 1-loop and at 2-loop order. The mass of the charged Higgs boson is implemented at the 1-loop level.

Apr. 20. 1999
A (also numerical irrelevant) bug has been fixed. Sign of mue (which appears in the Sbottom mixing contribution) has been corrected (also numerical negligible). The options have been changed and should be even more transparent now. The definition of the two different values that are given for the lighter Higgs-boson mass is now also given 'on-line' directly together with the printed result (and not only on the FeynHiggsFast home page).

Mar. 19. 1999
FeynHiggsFast is available.
Short approximation formula has been implemented in FeynHiggs, see hep-ph/9903404.

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