The study of the antikaon nucleon system at very low energies plays a key
role in the study of the strong interaction with strangeness, with important
impact in particle and nuclear physics and astrophysics. Exotic atoms
measurements, in particular kaonic hydrogen and deuterium, allow to
determine the s-wave antikaon-nucleon ispospin dependent scattering lengths.
Taking advantage of the excellent quality kaon beam delivered by the DAFNE
collider in Frascati (Italy) combined with new experimental techniques, as
fast and very precise X ray detectors, like the Silicon Drift Detectors, we
have performed unprecedented measurements in the low-energy strangeness
sector in the framework of SIDDHARTA . The most
precise kaonic hydrogen measurement, together with an exploratory
measurement of kaonic deuterium, were performed by SIDDHARTA. Presently, a
major upgrade of the setup, SIDDHARTA-2 is being realized to perform a
precise measurement of kaonic deuterium and of other exotic atoms. The experiment at the DAFNE collider represents an opportunity which
is unique in the world in the strangeness sector.