Name: chen Date: 04/09/10-01:56:36 PM Z


Hi,

I have a puzzle in my calculations.
p0—initial vector meson
p3—final vector meson
p4—photon

epsC— the polarization Vector of initial vector meson
        PolarizationVector[p0,\[Mu]]
epsV— polarization Vector of final vector meson
        PolarizaitonVector[p3,\[Nu]]
epsG— polarization Vector of the photon
        PolarizationVector[p4,\[Rho]]
the amplitudes is part of my calculation after loop integral.

<<HighEnergyPhysics`FeynCalc`;

ScalarProduct[p0,p0]=m0^2;
ScalarProduct[p3,p3]=m3^2;
ScalarProduct[p4,p4]=0;
ScalarProduct[p0,p3]=m0*E3;
ScalarProduct[p0,p4]=m0*pf;
ScalarProduct[p3,p4]=E3*pf+pf^2;
pf=(m0^2-m3^2)/2/m0;
E3=Sqrt[pf^2+m3^2];

repV={epsC^2->PolarizationSum[\[Mu],ComplexIndex[\[Mu]],p0],
      epsV^2->PolarizationSum[\[Nu],ComplexIndex[\[Nu]],p3],
      epsG^2->PolarizationSum[\[Rho],ComplexIndex[\[Rho]]]};
Amp=epsC*epsV*epsG*LC[\[Mu],\[Nu],\[Lambda],\[Tau]]*FV[p3,\[Rho]]*
    FV[p3,\[Lambda]]*FV[p4,\[Tau]];
AmpStar=ComplexConjugate[Amp];
CS=Amp*AmpStar;
CS=Expand[CS];
CS=CS/.repV;
CS=Expand[CS];
CS=Contract[CS];
CS/.{m0->2,m3->1}

The final results is -9/2<0.

I use mathematica 4 with FeynCalc4.1.1