We discuss a renormalization scheme for relativistic baryon chiral perturbation theory which provides a simple and consistent power counting for renormalized diagrams. The method involves finite subtractions of dimensionally regularized diagrams beyond the standard MS scheme of chiral perturbation theory to remove contributions violating the power counting. This is achieved by a suitable renormalization of the parameters of the most general effective Lagrangian. In addition to its simplicity our method has the benefit that it can be easily applied to multiloop diagrams. As an application we discuss the mass of the nucleon and compare the result with the expression of the infrared regularization of Becher and Leutwyler.
On the simple model of interacting massless and heavy scalar fields it is demonstrated that the technique of heavy baryon chiral perturbation theory reproduces the results of relativistic theory. Explicit calculations are performed for diagrams including two-loops. 03.70.+k 12.39.Fe,
We discuss conceptual aspects of renormalization in the context of effective field theories for the two-nucleon system. It is shown that, contrary to widespread belief, renormalization scheme dependence of the scattering amplitude can only be eliminated up to the order the calculations are performed. We further consider an effective theory for an exactly solvable quantum mechanical model which possesses a long-and short-range interaction to simulate pionful effective field theory. We discuss the meaning of low-energy theorems in this model and demonstrate their validity in calculations with a finite cutoff Λ as long as it is chosen of the order of the hard scale in the problem. Removing the cutoff by taking the limit Λ → ∞ yields a finite result for the scattering amplitude but violates the low-energy theorems and is, therefore, not compatible with the effective field theory framework.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.