No abstract

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 ϕ 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.

Kaonic atoms measure the antikaon-nucleus interaction at almost zero relative energy, allowing one to determine basic low-energy quantum chromodynamics (QCD) quantities, namely, the antikaon-nucleon ( K ¯ N) scattering lengths. The latter are important for extracting the sigma terms which are built on the symmetry breaking part of the Hamiltonian, thereby providing a measure of chiral and SU(3) symmetries breaking. After discussing the sigma terms and their relations to the kaonic atoms, we describe the most precise measurement in the literature of kaonic hydrogen, performed at LNF-INFN by the SIDDHARTA experiment. Kaonic deuterium is still to be measured, and two experiments are planned. The first, SIDDHARTA-2 at LNF-INFN was installed on DA Φ NE in spring 2019 and will collect data in 2020. The second, E57 at J-PARC, will become operative in 2021.

No abstract

No abstract