Chiral effective field theory for nuclear matter with long- and short-range multi-nucleon interactions
Abstract:We derive a novel chiral power counting scheme for in-medium chiral perturbation theory with explicit nucleonic and pionic degrees of freedom coupled to external sources. It allows for a systematic expansion taking into account local as well as pion-mediated inter-nucleon interactions. Based on this power counting, one can identify classes of non-perturbative diagrams that require a resummation. Within this scheme, the pion self-energy in asymmetric nuclear matter is analyzed and calculated up-to-and-including next-to-leading order (NLO). It is shown that the corrections involving in-medium nucleon–nucleon interactions cancel between each other at NLO. As a result, there are no corrections up to this order to the linear density approximation for the in-medium pion self-energy.
Document Type: Research Article
Publication date: January 1, 2010