Isospin dependence of the eta' meson production in nucleon--nucleon collisions

TL;DR

This study investigates the isospin dependence of eta' meson production in nucleon-nucleon collisions to understand differences in cross sections and the eta' meson's internal structure, including potential gluonium components.

Contribution

It provides new experimental insights into eta' production mechanisms in proton-neutron collisions and compares isospin channels to explore meson structure.

Findings

Significant difference in eta' production cross sections between pp and pn collisions.

Insights into the isospin dependence of eta' meson production.

Potential evidence for gluonium components in eta' meson.

Abstract

According to the quark model, the masses of eta and eta' mesons should be almost equal. However, the empirical values of these masses differ by more than the factor of two. Similarly, though the almost the same quark-antiquark content, the total cross section for the creation of these mesons close to the kinematical thresholds in the pp --> ppX reaction differs significantly. Using the COSY-11 detection setup we intend to determine whether this difference will also be so significant in the case of the production of these mesons in the proton-neutron scattering. Additionally, the comparison of the pp --> pp eta' and pn --> pn eta' total cross sections will allow to learn about the production of the eta' meson in the channels of isospin I = 0 and I = 1 and to investigate aspects of the gluonium component of the eta' meson.