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

Understand

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 [1].

• 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.