Name: Tramontano Francesco Date: 09/01/02-02:13:30 PM Z


Hi Frederick,

I have some questions:

1) I will try the updated version, however, to continue the calculation I
replaced the whole FA-Quark-Gluon-Vertex with the FC QuarkGluonVertex in
this way:

ampFA = CreateFeynAmp[ff];
ampPL = PickLevel[Classes][ampFA];
ampF1 = ToFA1Conventions[ampPL];
ampF1 /. {((-I)*GStrong*DiracGamma[LorentzIndex[cli_]].DiracGamma[6]*
              SUNT[_[_, 1], _, _] -
            I*GStrong*DiracGamma[LorentzIndex[cli_]].DiracGamma[7]*
              SUNT[_[_, 1], _, _]) ->
        QuarkGluonVertex[cli,
          a], ((-I)*GStrong*DiracGamma[LorentzIndex[cli_]].DiracGamma[6]*
              SUNT[_[_, 2], _, _] -
            I*GStrong*DiracGamma[LorentzIndex[cli_]].DiracGamma[7]*
              SUNT[_[_, 2], _, _]) ->
        QuarkGluonVertex[cli,
          b],
      DiracSpinor[mom_, mas_] -> Spinor[mom, mas], SumOver[_[_, _], _] ->
1,
      SumOver[_[_, _], _, _] -> 1,
      GStrong -> Gstrong, Index[Gluon, 1] -> “a”, Index[Gluon, 2] -> “b”};

and used the FC SUN machinary. Is there any problem in doing so?

2) In the updated version too it seems that there is a problem in FAToFC
when a vector boson is in the initial state: renaming momenta some
particle in FA notation became antipaticle in FC notation

I tried with:

tt = CreateTopologies[0, 2 -> 1];
aa = InsertFields[tt, {V[3], F[3, {1}]} -> {F[4, {1}]},
      InsertionLevel -> Classes, Model -> “SMQCD”, GenericModel ->
“Lorentz”];

after FAToFC d-quark momentum K1 become -p3. (different momentum
conservation conventions?)

3) In performing integration over loop momenta I don’t succeded to use
FeynmanParametrize1, FeynmanReduce and FeynmanDoIntegrals, maibe I was
inserting wrong input. Could you write an example? Is there some package
with evaluated scalar function integrals in FC or elsewhere?

Thank you very much for the big support
Francesco Tramontano