•Generation of topologies and insertion of fields

mesonstop = CreateTopologies[1, 1 -> 2, Adjacencies -> {3, 4, 5}, ExcludeTopologies -> {SelfEnergies, WFCorrections}, CountertermOrder -> 0] ;

Paint[mesonstop, AutoEdit -> False, ColumnsXRows -> {3, 2}] ;

[Graphics:../HTMLFiles/index_11.gif]

$InsertOnly = {Vector0[0] -> {Incoming, Outgoing, External}, AxialVector0[0] -> {Incoming, Outgoing, External}, Vector1[0] -> {Incoming, Outgoing, External}} ;

$VerticesSpecifications = {{VertexFields -> {Pion[0], Pion[0], Pion[0], Pion[0]}, PhiModel -> ChPT2, PerturbationOrder -> {2}, CouplingSign -> 1, XFileName -> Automatic}, {VertexFields -> {Pion[0], Pion[0], Photon[0]}, PhiModel -> ChPTPhoton2, PerturbationOrder -> {2}, CouplingSign -> 1, XFileName -> Automatic}, {VertexFields -> {Pion[0], Pion[0], Pion[0], Pion[0], Photon[0]}, PhiModel -> ChPTPhoton2, PerturbationOrder -> {2}, CouplingSign -> 1, XFileName -> Automatic}} ;

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

mesontreeinsert = InsertFields[mesonstop, {Photon[0]} -> {Pion[0, {i1}], Pion[0, {i2}]}, Model -> "Automatic", GenericModel -> "Automatic", InsertionLevel -> Classes] ;

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

[Graphics:../HTMLFiles/index_17.gif]

Converted by Mathematica  (July 10, 2003)