Non-perturbative methods for a chiral effective field theory of finite density nuclear systems

Journal Article · Tue Feb 15 00:00:00 EST 2011 · Annals of Physics (New York)

DOI:https://doi.org/10.1016/j.aop.2010.06.012· OSTI ID:21579854

Lacour, A ^[1]; Meissner, U -G ^[1]

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1. Helmholtz-Institut fuer Strahlen- und Kernphysik (Theorie), Bethe Center for Theoretical Physics, Universitaet Bonn, D-53115 Bonn (Germany)

Recently we have developed a novel chiral power counting scheme for an effective field theory of nuclear matter with nucleons and pions as degrees of freedom . It allows for a systematic expansion taking into account both local as well as pion-mediated multi-nucleon interactions. We apply this power counting in the present study to the evaluation of the pion self-energy and the energy density in nuclear and neutron matter at next-to-leading order. To implement this power counting in actual calculations we develop here a non-perturbative method based on Unitary Chiral Perturbation Theory for performing the required resummations. We show explicitly that the contributions to the pion self-energy with in-medium nucleon-nucleon interactions to this order cancel. The main trends for the energy density of symmetric nuclear and neutron matter are already reproduced at next-to-leading order. In addition, an accurate description of the neutron matter equation of state, as compared with sophisticated many-body calculations, is obtained by varying only slightly a subtraction constant around its expected value. The case of symmetric nuclear matter requires the introduction of an additional fine-tuned subtraction constant, parameterizing the effects from higher order contributions. With that, the empirical saturation point and the nuclear matter compressibility are well reproduced while the energy per nucleon as a function of density closely agrees with sophisticated calculations in the literature.

• OSTI ID: 21579854
• Journal Information: Annals of Physics (New York), Vol. 326, Issue 2; Other Information: DOI: 10.1016/j.aop.2010.06.012; PII: S0003-4916(10)00138-7; Copyright (c) 2010 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0003-4916
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CHIRALITY
COMPRESSIBILITY
DEGREES OF FREEDOM
DENSITY
ENERGY DENSITY
EQUATIONS OF STATE
FIELD THEORIES
MANY-BODY PROBLEM
NUCLEAR MATTER
NUCLEON-NUCLEON INTERACTIONS
NUCLEONS
PARTIAL WAVES
PERTURBATION THEORY
PIONS
SATURATION
SELF-ENERGY
SYMMETRY
BARYON-BARYON INTERACTIONS
BARYONS
BOSONS
ELEMENTARY PARTICLES
ENERGY
EQUATIONS
FERMIONS
HADRON-HADRON INTERACTIONS
HADRONS
INTERACTIONS
MATTER
MECHANICAL PROPERTIES
MESONS
PARTICLE INTERACTIONS
PARTICLE PROPERTIES
PHYSICAL PROPERTIES
PSEUDOSCALAR MESONS