Kinematic Fingerprints of a Nucleon-Triggered $V_{\mathcal{B}}$ in Rare ${\eta }^{(\prime )}\to {\pi }^0(\eta )\gamma \gamma$ Decays on Nucleon Targets

Yaroslav Balytskyi

The nucleon-triggered vector boson $V_{\mathcal{B}}$ is a hypothetical particle motivated by a statistically significant discrepancy between the KLOE measurement, $\mathrm{BR}^{η\ri…