Name: Jon Palmer (email_not_shown)
Date: 09/15/05-02:10:53 PM Z

Dear All,

Can anyone enlighten me as to how to handle complex infinities that arise in tadpole diagrams involving massless particles? For instance the following calculation in QED:

tops = CreateTopologies[1, 1 -> 1];
ins = InsertFields[tops[[2]], F[1, {1}] -> F[1, {1}], Model -> QED,
          InsertionLevel -> {Particles}];

Produces three diagrams whose amplitudes involve 'ComplexInfinity' due to the zero mass of the photon. How should these diagrams be handled by FeynArts/FeynCalc?

Many thanks

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