Decays of the η Mesons η/η' → πγγ and η' → ηγγ within the Nambu–Jona-Lasinio Model

The decays of the η mesons \({\eta \mathord{\left/ {\vphantom {\eta {\eta {\kern 1pt} '}}} \right. \kern-0em} {\eta {\kern 1pt} '}} \to \pi \gamma \gamma \) and \(\eta {\kern 1pt} ' \to \eta \gamma \gamma \) are considered within the Nambu–Jona-Lasinio model. It is shown that vector channels give the main contribution. An analysis of the influence of the decay constants of vector mesons on the widths of these processes is carried out taking into account the electromagnetic interactions of these mesons. The obtained results are in satisfactory agreement with experimental data.