Investigating low energy QCD with kaonic atoms: the SIDDHARTA experiment at DAFNE

Kaonic atoms measurements offer the key to unlock secrets of the low-energy QCD in the strangeness sector, a field still largely unexplored. Their experimental studies allow to ac- cess fundamental information, such as the antikaon-nucleon isospin dependent scattering lengths which are, in turn, vital information for understanding the mechanism of chiral symmetry bre- aking. In the past years, the studies of kaonic atoms received a big boost with the advent of new experimental techniques, as those pioneered by SIDDHARTA, based on the use of fast Silicon Drift Detectors for precision X-ray spectroscopy and of the ideal kaon beam offered by DAFNE. The precision achieved by SIDDHARTA at DAFNE in measuring kaonic helium 3 and 4 and kaonic hydrogen is unique. In this work we'll present the results of the measurement of the strong interaction induced shift and width of kaonic hydrogen 1s level, and the shift measurement of the