Effect of three-body forces on response functions in infinite neutron matter

TL;DR

This paper investigates how three-body forces influence the response functions of cold neutron matter, revealing significant effects on excited states and static responses using Landau parameters from chiral effective field theory.

Contribution

It introduces a detailed analysis of three-body forces' impact on neutron matter response functions within the RPA framework, including a new exact formula for static and long-wavelength limits.

Findings

Three-body forces significantly affect excited states.

Response functions are altered in static and long-wavelength limits.

A new exact formula for response functions is established.

Abstract

We study the impact of three-body forces on the response functions of cold neutron matter. These response functions are determined in the random phase approximation (RPA) from a residual interaction expressed in terms of Landau parameters. Special attention is paid to the non-central part, including all terms allowed by the relevant symmetries. Using Landau parameters derived from realistic nuclear two- and three-body forces grounded in chiral effective field theory, we find that the three-body term has a strong impact on the excited states of the system and in the static and long-wavelength limit of the response functions for which a new exact formula is established.