Home of FeynHiggs (real)

FeynHiggs is a Fortran code for the 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/9812320.
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.
The approximation formulas (also used in FeynHiggsFast) are given in hep-ph/9903404.
For details about the new renormalization at the one-loop level (see update on Sep. 24th 2001) see hep-ph/0202166 by by M. Frank, S. Heinemeyer, W. Hollik and G. Weiglein.
More information about the NMFV models implemented into FeynHiggs, see hep-ph/0210335 by A. Curiel, M. Herrero and D. Temes (and references therein).

Newest version: FeynHiggs1.5.1

Last update: Dec. 04. 2003
What happened (FeynHiggs1.5.1):
A bug in the DRbar to OS transition (with iteration) for the sbottom sector has been removed (thanks to Jean-Luc Kneur and Pietro Slavich).
The subroutine 'phi' for the two-loop calculation has been made 'safer' against instabilities.

History:
Oct. 27. 2003 (FeynHiggs1.5):
The evaluation of the leading corrections coming from NMFV models are included (parameterized by the new input parameter lambda_t)
The transition from DRbar to on-shell for the stop and sbottom masses have been extended to include (besides the O(alpha_s corrections) also the O(alpha_t,b) corrections (thanks go to Pietro Slavich).
Another bug in the O(alpha_t alpha_b) and O(alpha_b²) corrections in the Higgs sector has been removed (thanks go again to Pietro Slavich).

Jul. 21. 2003 (FeynHiggs1.4.1)
A bug in the O(alpha_t alpha_b) and O(alpha_b²) corrections has been removed (thanks go to Pietro Slavich). The bug had only an effect if mu > 0, i.e. where the corrections of O(alpha_t alpha_b) and O(alpha_b²) are small.

Jul. 17. 2003 (FeynHiggs1.4):
The remaining O(alpha_t alpha_b) and O(alpha_b²) corrections have been included (thanks go to Pietro Slavich), which can yield non-negligible contributions for large (-mu) and tan beta. The corrections are taken from hep-ph/0305127 (A. Dedes, G. Degrassi, P. Slavich)
Furthermore now routines for the SUSY contribution to g-2 of the muon and the evaluation of BR(b -> s gamma) is contained in the code for further cross checks.

May 08. 2003 (FeynHiggs1.3.1):
A bug in the routine for the pole mass search has been fixed. For very low M_A values (below 20 GeV or so) it could result in a wrong value for the heavy CP-even Higgs mass.

Dez. 02. 2002 (FeynHiggs1.3):
All major recent changes are summarized in hep-ph/0212020 (G. Degrassi, S. Heinemeyer, W. Hollik, P. Slavich and G. Weiglein).

The remaining O(alpha_s alpha_b) corrections have been included (thanks go to Pietro Slavich), which can yield non-negligible contributions for large (-mu) and tan beta. The corrections are taken from hep-ph/0206101 (A. Brignole, G. Degrassi, P. Slavich, F. Zwirner)

The presumably leading O(alpha_t alpha_b) corrections have been included, via their contribution to "Delta m_b", see hep-ph/9912516 (M. Carena, D. Garcia, U. Nierste, C. Wagner) and hep-ph/0206101 (A. Brignole, G. Degrassi, P. Slavich, F. Zwirner). A new option for the inclusion of these corrections has been added.

The renormalization scale for the subleading one-loop corrections entering via delta tan beta and for the O(alpha_t²) corrections is now forced to be the same.

The two-loop O(alpha_s alpha_t) corrections have been reformatted. The files are now much shorter (by a factor of 5) and faster. (Thanks go to T. Hahn.)

Some common blocks have been renamed to make the inclusion of FeynHiggs into other codes easier.

The two-loop O(alpha_s alpha_t) have been made much shorter and correspondingly faster.

Mar. 25. 2002 (FeynHiggs1.2.2):
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.

Mar. 05. 2002 (FeynHiggs1.2.1):
Bug in the approximation formula fixed: wrong result was produced if the new non-logarithmic O(alpha_t²) had been used. I.e. this bug existed only from 29Jan02 till 05Mar02.

Jan. 29. 2002 (FeynHiggs1.2):
Inclusion of the non-logarithmic O(alpha_t²) as presented in hep-ph/0112177 (A. Brignole, G. Degrassi, P. Slavich, F. Zwirner). First plots showing the effect of this new contribution can be found in hep-ph/0202166.

Sep. 24. 2001:
The renormalization at the one-loop level has been modified. In particular, an MSbar renormalization for tan beta has been used (at the scale m_t), see hep-ph/0202166. The renormalization in the new version does no longer require the derivative of the A boson self-energy. This leads to a more stable behavior around thresholds, e.g. M_A = 2 m_t, and avoids unphysically large contributions in certain regions of the MSSM parameter space. Besides stabilizing the one-loop result, the values of m_h are increased by 1-2 GeV in the three benchmark scenarios. For details and exemplefying plots click on New version .

Apr. 03. 2000:
The new version corresponds to the one used for the LEP benchmark scans. (Results obtained with FeynHiggs are given here.) It furthermore contains the evaluation the effective mixing angle of the CP-even Higgs sector as well as the calculation of the mass of the charged Higgs boson at the 1-loop level.
Another new feature is the possibility of using MSbar parameters as input parameters. According to hep-ph/0001002 (where an approximation of the relevant formulas is presented) the MSbar parameters are transformed into On-Shell parameters, which are then used for the calculation within FeynHiggs.

Apr. 20. 1999:
A (numerical irrelevant) bug in Hhmasssr.f has been fixed. The control letters (a remnant from the old DOS times) have been removed.

Jan. 23. 1999:
Pure Yukawa calculation from the top/stop sector added, so possilbe numerical instabilities due to thresholds can be detected.
One-loop bottom/sbottom sector stabilized (non perturbative regime with large tan(beta) and large |mue| corrected.)
Some Fortran bugs fixed. Compilation should be more stable now :-)

Sep. 01. 1998:
Calculation of \Delta \rho: complete correction O(alpha alpha_s) included (gluino contribution added.) Files that changed: FeynHiggs.f, delrhosub.f, Introduction.txt, makefile . New files: delrhoGluino[code,sum,var].f

Aug. 26. 1998:
Bug in def2.f fixed (mt = 175 GeV had been forced there, only relevant if stop masses had been used as input parameters)

Aug. 25. 1998:
Introduction improved, definition of mu clarified

Aug. 24. 1998:
FeynHiggs is available

Old version of FeynHiggs

-> corresponds to the published version hep-ph/9812320.
Bug fixes and other improvements after Sep.01.1998 are not included.

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