The Casimir-Polder interaction between two neutrons and possible relevance to tetraneutron states

TL;DR

This paper derives the extended Casimir-Polder interaction between two neutrons using Chiral Effective Theory, considering high-energy effects, and explores its potential relevance to tetraneutron states.

Contribution

It presents a novel derivation of neutron-neutron Casimir-Polder interaction incorporating high-energy effects and examines its implications for tetraneutron states.

Findings

Neutron-neutron CP interaction is significantly influenced by high-energy effects.

The 4-neutron CP interaction may impact the understanding of tetraneutron resonances.

The study provides a framework for assessing long-range forces in neutron systems.

Abstract

We present a summary of our recent publication concerning the derivation of the extended Casimir-Polder dispersive interaction between two neutrons. Dynamical polarizations of the neutrons, recently derived within Chiral Effective Theory are used for the purpose. An account of the higher frequency/energy behavior of these entities related to the opening of one-pion production channel and the excitation of the $\Delta$ resonance are taken into consideration in our derivation of the CP interaction. The neutron-neutron system in free space is treated in details so are the neutron-wall and the wall-neutron-wall systems. The case of tetraneutron (a 4 neutron system) in a resonant state is then briefly considered. The 4n CP interaction is evaluated to assess its potential relevance to the ongoing debate concerning the nature of the tetraneutron.