SIDDHARTA-2 apparatus for kaonic atoms research on the DAΦNE collider

SIDDHARTA-2 is a state-of-the-art experiment designed to perform measurements of kaonic atoms, which are exotic atoms composed of a negatively charged kaon orbiting nucleus. These atoms constitute an exceptional probe for investigating the strong interaction in the non-perturbative regime involving strangeness. The experiment is installed at the DAΦNE electron-positron collider of the INFN National Laboratory of Frascati (INFN-LNF) in Italy, aiming to perform the first-ever measurement of the 2p → 1s X-ray transitions in kaonic Deuterium, a crucial step towards determining the isospin-dependent antikaon-nucleon scattering lengths. Based on the experience gained with the previous SIDDHARTA experiment, which performed the most precise measurement of the kaonic Hydrogen 2p → 1s X-ray transitions, the present apparatus has been upgraded with innovative X-Ray Silicon Drift Detectors (SDDs), distributed around a cryogenic gaseous target placed in a vacuum chamber at a short distance above the interaction region of the collider, two new veto systems and a charged kaon detector. The current work presents a comprehensive description of the SIDDHARTA-2 setup, including the optimization of its various components during the commissioning phase of the collider.