# Eta-nucleon and eta-prime-nucleon coupling constants in QCD and the role of gluons

## TL;DR

This paper calculates the eta and eta-prime meson-nucleon coupling constants using QCD sum rules, highlighting the significant role of anomalous gluons and OZI-rule violation in these interactions.

## Contribution

It introduces a novel QCD sum rule approach to determine eta and eta-prime-nucleon couplings, emphasizing gluon contributions and OZI-rule violation.

## Key findings

- Anomalous gluons significantly influence coupling constants.
- OZI-rule violation is substantial in eta and eta-prime interactions.
- Coupling constants are estimated at physical points through extrapolation.

## Abstract

Coupling constants of $\eta$ and $\eta^{\prime}$ mesons with nucleons have been calculated using the method of QCD sum rules. Starting from vacuum-to-meson correlation function of interpolating fields of two nucleons, its matrix element with respect to nucleon spinors has been considered. Coupling constants at the physical points have been estimated from extrapolation of results obtained at two other points. Anomalous glue has been found to give substantial contribution to the coupling constants and also accounts for a significant OZI-rule violation.