FormCalc 2 README file

FormCalc calculates and simplifies one-loop Feynman diagrams. It reads
amplitudes generated with FeynArts and returns the results in a way well
suited for further numerical (or analytical) evaluation.

Internally, FormCalc delegates the hard work (e.g. working out fermionic
traces) to FORM by Jos Vermaseren. Thus FormCalc is merely a driver that
threads the FeynArts amplitudes through FORM in an appropriate way. The
idea is rather simple: FormCalc prepares the symbolic expressions of the
diagrams in an input file for FORM, runs FORM, and retrieves the results.
This interaction is transparent to the user.

FormCalc combines the speed of FORM with the powerful instruction set of
Mathematica and the latter greatly facilitates further processing of the
results. Owing to FORM's speed, FormCalc can process, for example, the
1000-odd one-loop diagrams of elastic W-W scattering in the Standard Model
in about 5 minutes on an ordinary Pentium PC.

One important feature of FormCalc is that it automatically gathers spinor
chains, scalar products of and epsilon tensors contracted with momenta
and/or polarization vectors and introduces abbreviations for them. In
calculations with non-scalar external particles where such objects are
ubiquitous, code produced from the FormCalc output (say, in Fortran) can
be significantly faster than without the abbreviations. For further
evaluating spinor chains, FormCalc provides a function which calculates
helicity matrix elements.

The FormCalc distribution contains a package of programs for the
numerical evaluation of FormCalc results and two demo calculations,
ZZ -> ZZ and e^+e^- -> t\bar t, to show how these programs are used.


Installation notes for the impatient:

- unpack the archive FormCalc2.tar.gz in some directory
  (presumably you did this already or else you wouldn't be reading
  this file)

- run ./compile to compile the C programs needed by FormCalc

- if you have FORM 2.0 or 2.1, but not 2.2 (type "form /dev/null"
  to find out), say
	patch < patch.Form2.0

For more detailed instructions see the manual in FC2Guide.ps.gz.

The latest version of FormCalc can be downloaded from
http://www.feynarts.de/formcalc.

Enjoy!

Thomas Hahn
hahn@feynarts.de

