Eta-mesic nuclei in relativistic mean-field theory

TL;DR

This study investigates eta-mesic nuclei using relativistic mean-field theory, showing that bound states depend on eta-nucleon interaction parameters and predicting their experimental observability under certain conditions.

Contribution

It introduces a theoretical framework combining chiral perturbation theory with relativistic mean-field models to predict eta-mesic nuclei and their properties.

Findings

Eta-mesic bound states exist for specific eta N scattering lengths and imaginary potentials.

Bound states are more likely for scattering lengths between 0.75 and 1.05 fm with V0 around -15 MeV.

No bound states are predicted if scattering length is below 0.5 fm or V0 exceeds 30 MeV.

Abstract

With the eta-nucleon (eta N) interaction Lagrangian deduced from chiral perturbation theory, we study the possible eta-mesic nuclei in the framework of relativistic mean-field theory. The eta single-particle energies are sensitive to the eta N scattering length, and increase monotonically with the nucleon number A. If the scattering length is in the range of a^{eta N}=0.75-1.05 fm and the imaginary potential V_{0}-15 MeV, some discrete states of C, O and Ne eta bound states should be identified in experiments. However, when the scattering length a^{eta N}< 0.5 fm, or the imaginary potential V_{0} > 30 MeV, no discrete eta meson bound states could be observed in experiments.