Name: K.J. Healey Date: 02/01/13-12:32:34 AM Z
Currently I am doing the diagrams for a 2->3 and I noticed that
CreateFCAmp/FAToFC incorrectly assigns the momenta to a spinor.
Basically it takes an incoming photon momenta and assigns that to the
spinor rather than the quark. I cannot attach an example (do I need to
be a subscriber?). So here is example code.
FIRST the correct way (a 2->1 example)
$LoadFeynArts = True;
$LoadPhi = True;
«HighEnergyPhysics`FeynCalc`;
tops = CreateTopologies[0, 2 -> 1, ExcludeTopologies -> {},
Adjacencies -> 3];
inserted = InsertFields[tops, {F[3, {1}], V[1]} ->
{F[3, {1}]},
Model -> “SMQCD”, ExcludeParticles -> {S[a_],
V[1], V[2], V[3]}];
Paint[inserted, PaintLevel -> {Classes}];
CreateFeynAmp[inserted]
CreateFCAmp[inserted]
(* THIS IS CORRECT AS FAR AS I CAN TELL, LOOK AT THE SPINOR MOMENTA ASSIGNMENTS. IT CHANGED {P1,P2-> K1} to {P1, P2-> P3}*)
(* NOW LETS DO IT FOR A 2->3 *)
tops = CreateTopologies[0, 3 -> 2, ExcludeTopologies -> {},
Adjacencies -> 3];
inserted = InsertFields[
tops, {F[3, {1}], -F[4, {1}], V[1]} ->
{F[3, {1}], -F[4, {1}]},
Model -> “SMQCD”, ExcludeParticles -> {S[a_],
V[1], V[2], V[3]}];
Paint[inserted, PaintLevel -> {Classes}];
(* LOOK AT THE FIRST LINE, NOTICE THE MOMENTA ASSIGNMENTS, THE PHOTON IS P3 THEN LOOK AT THE SPINOR ASSIGNMENTS IN THE CREATEFCAMP, ITS INCORRECT*)
CreateFeynAmp[inserted]
CreateFCAmp[inserted]