Characterization of the SIDDHARTA-2 luminosity monitor

A luminosity monitor, based on plastic scintillator detectors, has been developed for the SIDDHARTA-2 experiment aiming to perform high precision measurements of kaonic atoms and was installed in 2020 on the DAΦNE e+e− collider at LNF (Laboratori Nazionali di Frascati, INFN). The main goal of this system is to provide the instantaneous and integrated luminosity of the DAΦNE facility by measuring the rate of K+K− correlated pairs emitted by the meson decay. This task requires an accurate timing of the DAQ signals, as well as timing resolution below 1 ns, in order to disentangle the K± signals from the background minimum ionizing particles (MIPs) produced during the e+ e− collisions at DAΦNE. In this paper the luminosity monitor concept as well as its laboratory characterization and the first results inside DAΦNE are presented.