Name: Rolf Mertig Date: 02/29/12-02:38:15 AM Z


Hm, be careful: you cannot copy and paste FeynCalc output as input.

simple things just seem to work fine:

Mathematica 8.0 for Linux x86 (64-bit)
Copyright 1988-2011 Wolfram Research, Inc.

In[1]:= !!ben
<<HighEnergyPhysics`fc`

FI; IP = InputForm;

constraint =
  FeynCalcInternal[
    FV[p, muPAT] FV[p, nuPAT] ->
     PolarizationSum[mu, nu, p1]] /. {muPAT :> mu_, nuPAT :> nu_};

Print[” “];
Print[“check constraint : “, IP @ constraint ];
Print[” “];
tmp = FCI[ FV[p,alpha] FV[p,beta] ];

Print[“contract and using the constraint : “,
IP @ FeynCalcExternal @ Contract[tmp /. constraint]]

In[1]:= <<ben
Loading FeynCalc from /home/rolfm/HighEnergyPhysics
FeynCalc 8.1.0 Type ?FeynCalc for help or visit http://www.feyncalc.org/
$PrePrint is set to FeynCalcForm. Use FI and FC to change the display format.
Loading FeynArts, see www.feynarts.de for documentation
FeynArts 3.4 patched for use with FeynCalc

check constraint : Pair[LorentzIndex[mu_], Momentum[p]]*
   Pair[LorentzIndex[nu_], Momentum[p]] ->
  -Pair[LorentzIndex[mu], LorentzIndex[nu]] +
   (Pair[LorentzIndex[mu], Momentum[p1]]*
      Pair[LorentzIndex[nu], Momentum[p1]])/Pair[Momentum[p1], Momentum[p1]]

contract and using the constraint :
 -MT[alpha, beta] + (FV[p1, alpha]*FV[p1, beta])/SP[p1, p1]

In[2]:=