Zero-Mass Approach to Counterterms

The following sections are included:

• Infrared Power Counting

• Infrared Rearrangement

  • The R-Operation for Massless Diagrams

  • Zero-Mass Simplifications for Z_φ

• Infrared Divergences in Dimensional Regularization

  • Nonexceptional External Momenta

  • Exceptional External Momenta

  • Massless Tadpole Diagrams

• Subtraction of UV- and IR-divergences: R^*-Operation

  • Example for Subtraction of IR- and UV-Divergences

  • Graph-Theoretic Notations

  • Definition of R^*- and -Operation

  • Construction of Infrared Subtraction Terms of Subdiagrams

  • IR-Counterterms

• Examples for the -Operation

• Appendix 12A Proof of Interchangeability of Differentiation and -Operation

• Notes and References