Manifestly Lorentz-Invariant Baryon Chiral Perturbation Theory

Abstract

A successful effective field theory program requires besides the most general effective Lagrangian a perturbative expansion scheme for observables in terms of a consistent power counting method. We discuss a renormalization scheme for manifestly Lorentz-invariant baryon chiral perturbation theory generating a simple and consistent power counting for renormalized diagrams. The approach may be used in an iterative procedure to renormalize higher-order loop diagrams and also allows for implementing a consistent power counting when vector mesons are explicitly included.

Comments: 4 pages, 2 figures, invited talk at International Conference on QCD and Hadronic Physics, Beijing, China, 16-20 June 2005