**Next message:**Vladyslav Shtabovenko: "Re: Error! DiracTrick has encountered a fatal problem and must abort the computation. The problem reads: Incorrect combination of dimensions and g^5 scheme!"**Previous message:**Vladyslav Shtabovenko: "UV-Divergences of 1-loop integrals"**Next in thread:**Vladyslav Shtabovenko: "Re: Error! DiracTrick has encountered a fatal problem and must abort the computation. The problem reads: Incorrect combination of dimensions and g^5 scheme!"**Reply:**Vladyslav Shtabovenko: "Re: Error! DiracTrick has encountered a fatal problem and must abort the computation. The problem reads: Incorrect combination of dimensions and g^5 scheme!"**Messages sorted by:**[ date ] [ thread ] [ subject ] [ author ]**Mail actions:**[ respond to this message ] [ mail a new topic ]

Hi! I'm experiencing an issue when trying to calculate the squared amplitude.

The code is

FCClearScalarProducts[];

{coef0 = u Sqrt[\[Alpha]] g/2, coef1 = 1/(32 Pi s)};

{ScalarProduct[k1, k1] = ScalarProduct[k2, k2] = 0,

ScalarProduct[p1, p1] = ScalarProduct[p2, p2] = 0,

ScalarProduct[p3, p3] = m^2,

ScalarProduct[k1, k2] = s/2, ScalarProduct[k1, p1] = -t1/2,

ScalarProduct[k1, p2] = (s1 + t1 - t2)/2,

ScalarProduct[k1, p3] = (s - s1 + t2)/2,

ScalarProduct[k2, p1] = (s - s2 + t1)/2,

ScalarProduct[k2, p2] = (s2 + t2 - t1 - m^2)/2,

ScalarProduct[k3, p3] = (m^2 - t2)/2, ScalarProduct[p1, p2] = s1/2,

ScalarProduct[p1, p3] = (s - s1 - s2)/2,

ScalarProduct[p2, p3] = (s2 - m^2)};

f1 = coef0 PolarizationVector[

k2, \[Mu]] SpinorUBar[k1,

0].GA[\[Mu]].QuarkPropagator[{k1 + k2, 0},

Explicit -> True].GA[\[Nu]].SpinorU[p1,

0] (-MetricTensor[\[Nu], \[Alpha]] +

FourVector[

k1 + k2 - p1, \[Nu]] FourVector[k1 + k2 - p1, \[Alpha]]/

mW^2) PropagatorDenominator[k1 + k2 - p1,

mW] SpinorVBar[p2, 0].GA[\[Alpha]].(1 - GA5). SpinorU[p3, m] // FCI

f1star = ComplexConjugate[f1]

m11 = DoPolarizationSums[f1 f1star, k2, 0]

m22 = FermionSpinSum[m11] /. DiracTrace -> TR // Contract // Simplify

Mfinal = m22

dsigbardz = coef1 Mfinal

It displays the amplitude correctly and evaluates its complex conjugation, but faols when calculating the fermion polarization sum with the error

"Error! DiracTrick has encountered a fatal problem and must abort the computation. The problem reads: Incorrect combination of dimensions and g^5 scheme!"

What is the reason for this?

**Next message:**Vladyslav Shtabovenko: "Re: Error! DiracTrick has encountered a fatal problem and must abort the computation. The problem reads: Incorrect combination of dimensions and g^5 scheme!"**Previous message:**Vladyslav Shtabovenko: "UV-Divergences of 1-loop integrals"**Next in thread:**Vladyslav Shtabovenko: "Re: Error! DiracTrick has encountered a fatal problem and must abort the computation. The problem reads: Incorrect combination of dimensions and g^5 scheme!"**Reply:**Vladyslav Shtabovenko: "Re: Error! DiracTrick has encountered a fatal problem and must abort the computation. The problem reads: Incorrect combination of dimensions and g^5 scheme!"**Messages sorted by:**[ date ] [ thread ] [ subject ] [ author ]**Mail actions:**[ respond to this message ] [ mail a new topic ]

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