•Generation of topologies and insertion of fields

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

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_34.gif]

Converted by Mathematica  (July 10, 2003)