Name: Rolf Mertig (email_not_shown)
Date: 02/11/10-11:54:19 PM Z


Hello,

find below my quick attempt to get you going with the tensor integral.
You need to do the final integrals probably by partial fraction
decompoisition etc.
(I am using my development version of FeynCalc, but it will work with older versions the same way).

Regards,
-----
Rolf Mertig
GluonVision GmbH
Berlin, Germany
-----

In[1]:= !!tensorintegral.m
<<HighEnergyPhysics`FeynCalc` ;
Amp = FVD[q,mu] FVD[q,nu] FVD[q,al] FVD[q,be] FAD[{q,mD},{q,Lambda},
{q,Lambda}, {p3+q,m1},{q-p4,m2}];
Format[LineBreak[_]] := "";
Print["Amp = ", Amp];
test = Isolate[Factor1 @ Collect2[TID[Amp,q], q] // FCE, q, IsolateNames ->
T];
Print["\nafter tensor integral decomposition : "];
Block[{T}, Print @ InputForm @ ReleaseHold @ test];
Print["\nwhere the T[i] are functions of "];
Print @ Cases2[DownValues[T],{MTD,SPD,FVD}]

In[1]:= <<tensorintegral.m
Loading FeynCalc from /home/rolf/fccvs/fc7/HighEnergyPhysics
Loading TARCER /home/rolf/fccvs/fc7/HighEnergyPhysics/Tarcer/tarcer25.mx
FeynCalc 7.0.0 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 PHI
Loading FeynArts, see www.feynarts.de for documentation
FeynArts 3.5 patched for use with FeynCalc
Amp = FAD[{q, mD}, {q, Lambda}, {q, Lambda}, {p3 + q, m1}, {-p4 + q, m2}]
  FVD[q, al] FVD[q, be] FVD[q, mu] FVD[q, nu]

after tensor integral decomposition :
-((FAD[{q, Lambda}, {q, Lambda}, {q, mD}, {p3 + q, m1}, {-p4 + q, m2}]*
     (-(SPD[p3, q]^4*T[2]^4*T[3]) - SPD[p3, q]^3*SPD[p4, q]*T[2]^4*T[4] +
       SPD[p3, q]^2*SPD[p4, q]^2*T[2]^4*T[5] -
       SPD[p3, q]*SPD[p4, q]^3*T[2]^4*T[6] + SPD[p4, q]^4*T[2]^4*T[7] +
       SPD[p3, q]^2*SPD[q, q]*T[2]^5*T[8] -
       SPD[p3, q]*SPD[p4, q]*SPD[q, q]*T[2]^5*T[9] +
       SPD[p4, q]^2*SPD[q, q]*T[2]^5*T[10] + SPD[q, q]^2*T[2]^6*T[11]))/
   (D*T[1]*T[2]^8))

where the T[i] are functions of
{FVD[p3, al], FVD[p3, be], FVD[p3, mu], FVD[p3, nu], FVD[p4, al],
 FVD[p4, be], FVD[p4, mu], FVD[p4, nu], MTD[al, be], MTD[al, mu],
 MTD[al, nu], MTD[be, mu], MTD[be, nu], MTD[mu, nu], SPD[p3, p3],
 SPD[p3, p4], SPD[p4, p4]}

In[2]:= TimeUsed[]

Out[2]= 8.55



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