Kaon-nucleon interaction studied by kaonic X rays with DEAR at DAφNE

The scientific program and the experimental setup of the DEAR (DAφNE Exotic Atom Research) experiment on the new φ-factory DAφNE of Laboratori Nazionali di Frascati, are presented. The objective DEAR is to perform a 1% measurement of the shift, due to the strong interaction, of the Kα 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 KN physics and to understand SU(3) chiral symmetry breaking. DEAR looks as the major effort ever performed to study low energy KN interaction, capable to produce a real breakthrough in the field. (author)