Elsevier Science Home
Computer Physics Communications Program Library
Full text online from Science Direct
Programs in Physics & Physical Chemistry
CPC Home

[Licence| Download | New Version Template] admj_v2_0.tar.gz(181 Kbytes)
Manuscript Title: ZFITTER: a semi-analytical program for fermion pair production in e+e- annihilation, from version 6.21 to version 6.42
Authors: A. B. Arbuzov, M. Awramik, M. Czakon, A. Freitas, M. W. Grünewald, K. Mönig, S. Riemann, T. Riemann
Program title: ZFITTER version 6.42 (18 May 2005)
Catalogue identifier: ADMJ_v2_0
Distribution format: tar.gz
Journal reference: Comput. Phys. Commun. 174(2006)728
Programming language: FORTRAN 77.
Operating system: UNIX/LINUX, program tested under, e.g, HP-UX and PC/Linux.
Keywords: Quantum electrodynamics (QED), Standard Model, electroweak interactions, heavy boson Z, e+e--annihilation, fermion pair production, radiative corrections, initial state radiation (ISR), final state radiation (FSR), QED interference, SLD, LEP, ILC.
PACS: 12.15.-y, 13.66.Jn, 14.70.Hp Z bosons.
Classification: 11.5.

Does the new version supersede the previous version?: Yes

Nature of problem:
Fermion pair production is an important reaction for precision tests of the Standard Model, at LEP/SLC and future linear colliders at higher energies. For this purpose, QED, electroweak and QCD radiative corrections have to be calculated with high precision, including higher order effects. Multi parameter fits used to extract model parameters from experimental measurements require a program of sufficient flexibility and high calculational speed. ZFITTER combines these two aspects by employing analytical integrations of matrix elements and at most one-dimensional numerical integration, as well as a variety of flags defining the physics content used. The calculated predictions are typically at the per mille precision level, sometimes better.

Solution method:
Numerical integration of analytical formulae.

Reasons for new version:
Addition of substantial material into the code: covering of more reactions; more accurate description of existing reactions.

Summary of revisions:
New parts for predicting atomic parity violation and for neutrino pair production; more accurate higher order QED corrections for fermion pair production; two-loop corrections to the predictions of W mass and of the weak mixing angle.

Restrictions:
Fermion pair production is described below the top quark pair production threshold. Photonic corrections are taken into account with simple cuts on photon energy, or the energies and acollinearity of the two fermions, and one fermion production angle. The treatment of Bhabha scattering is less advanced.

Running time:
On a Pentium IV PC installation (2.8 GHz) using g77 under Linux 2.4.21, approximately 23 sec are needed to run the standard test of subroutine ZFTEST. This result is for a default/recommended setting of the input parameters, with all corrections in the Standard Model switched on. ZFTEST computes 12 cross-sections and cross-section asymmetries for 8 energies with 5 interfaces, i.e. about 360 cross-sections in 23 seconds.