Density-Dependent Neutron-Neutron Interaction from Subleading Chiral Three-Neutron Forces
Abstract
Three-nucleon forces are an essential ingredient for an accurate description of nuclear few- and many-body systems. However, implementing them directly in many-body calculations is technically very challenging. Thus, there is a need for an efficient approximation method. By closing one nucleon line to a loop, it is possible to derive effective in-medium nucleon-nucleon interactions that represent the underlying three-nucleon forces, as constructed in Chiral Effective Field Theory. Since three-neutron forces are equally as important for the computation of the equation of state for pure neutron matter, this work applies the aforementioned approach to the subleading chiral three-neutron forces, in particular the short-range terms and relativistic corrections. It is shown in this work that, while many contributions to the in-medium neutron-neutron interaction are - apart from a constant factor - identical to the terms in isospin-symmetric matter, some differ drastically. Moreover, previously vanishing terms yield now non-zero contributions. As a result of this work, density-dependent in-medium neutron-neutron potentials are now available for the implementation in nuclear many-body calculations, either in closed analytical form, or requiring at most one numerical integration.
Keywords
Cite
@article{arxiv.2009.11104,
title = {Density-Dependent Neutron-Neutron Interaction from Subleading Chiral Three-Neutron Forces},
author = {Lukas Treuer},
journal= {arXiv preprint arXiv:2009.11104},
year = {2021}
}
Comments
40 pages, 5 figures; Bachelor's thesis in physics, Technische Universit\"at M\"unchen, September 2020, supervised by Prof. Dr. Norbert Kaiser | The second version corrected the typing errors $(2p^2 - q^2/4) \rightarrow (2p^2 + q^2/4)$ in the ninth line of eq. (3.22), and $1/f_\pi^2 \rightarrow 1/f_\pi^4$ in the coefficients of eq. (3.30) and eq. (3.32)