Kaon-nucleon interaction studied by kaonic X rays with DEAR at DA Phi NE

The scientific program and the experimental. setup of the DEAR. (DA Phi NE Exotic Atom Research) experiment on the new phi-factory DA Phi NE of Laboratori Nazionali di Frascati, are presented. The objective of DEAR is to perform a 1% measurement of the shift, due to the strong interaction, of the K-alpha line of kaonic hydrogen and a similar precision measurement, performed for the first time, on kaonic deuterium. The aim is to investigate the low-energy <(K)over bar N> physics and to understand SU(3) chiral symmetry breaking. DEAR looks as the major effort ever performed to study low energy <(K)over bar N> interaction, capable to produce a real breakthrough in the field.