2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/206811The reaction $ pp \to pp η\to pp γe^+ e^-$ is discussed within a covariant effective meson-nucleon theory. The model is adjusted to data of the subreaction $pp \to pp η$. Our focus is on di-electrons from Dalitz decays of $η$ mesons, $η\to γγ^* \toγe^+e^-$, and the role of the corresponding transition form factor $F_{ηγγ^*}$. Numerical results are presented for the intermediate energy kinematics of HADES experiments.Nuclear Theorytext