Systematic few-body analysis of eta-d, eta-3He and eta-4He interaction at low energies

TL;DR

This paper employs N-body theory with separable expansions to analyze eta-meson interactions with light nuclei d, 3He, and 4He at low energies, providing insights into scattering lengths and subthreshold behaviors.

Contribution

It introduces a systematic few-body analysis using the Alt-Grassberger-Sandhas formalism with separable expansions for eta-nucleus interactions at low energies.

Findings

Determined eta-d, eta-3He, eta-4He scattering lengths.

Fitted low-energy eta production data on light nuclei.

Analyzed subthreshold eta-N scattering amplitude behavior.

Abstract

The Alt-Grassberger-Sandhas N-body theory is used to study interaction of eta-mesons with d, 3He, and 4He. Separable expansion of the subamplitudes is adopted to convert the integral equations into the quasi-two-body form. The resulting formalism is applied to fit the existing data for low-energy eta production on few-nucleon targets. On the basis of this fitting procedure the scattering lengths a_{eta d}, a_{eta 3He}, a_{eta 4He} as well as the subthreshold behaviour of the elementary eta-N scattering amplitude are obtained.