•Generation of the topology and insertion of the field

Construction of topologies:

mesonstop = (CreateCTTopologies[1, 1 -> 1] // DiscardCT // AddExternalLegs) /. Vertex[n__][i_ ? Positive] -> Vertex[n][-i] // Compare1 ;

Paint[mesonstop, AutoEdit -> False, SheetHeader -> False, Numbering -> True, ColumnsXRows -> {2, 1}] ;

[Graphics:../HTMLFiles/index_18.gif]

Specification of which coupling vectors are to be used. Not necessary, but speeds things up a lot (because it ommits all the big vertices).

$VerticesSpecifications = {{VertexFields -> {PseudoScalar[0][0], PhiMeson[0]}, PhiModel -> ChPT3, PerturbationOrder -> {2}, CouplingSign -> 1, XFileName -> Automatic}} ;

Field insertion:

InitializeModel["Automatic", GenericModel -> "Automatic", Reinitialize -> True] ;

mesontreeinsert = InsertFields[mesonstop, {PseudoScalar[0][0, {i1}]} -> {PseudoScalar[0][0, {i3}]}, Model -> "Automatic", GenericModel -> "Automatic", InsertionLevel -> Classes] ;

Graphical representation of the process:

Paint[mesontreeinsert, PaintLevel -> {Classes}, AutoEdit -> False, SheetHeader -> Automatic, ColumnsXRows -> {2, 1}, Numbering -> True] ;

[Graphics:../HTMLFiles/index_23.gif]

Converted by Mathematica  (July 10, 2003)