Unprecedented studies of the low-energy negatively charged kaons interactions in nuclear matter by AMADEUS

Abstract: The AMADEUS experiment aims to provide unique quality data of $K<sup>-$ hadronic interactions in light nuclear targets, in order to solve fundamental open questions in the non-perturbative strangeness QCD sector, like the controversial nature of the $\Lambda(1405)$ state, the yield of hyperon formation below threshold, the yield and shape of multi-nucleon $K<sup>-$ absorption, processes which are intimately connected to the possible existence of exotic antikaon multi-nucleon clusters. AMADEUS takes advantage of the DA$\Phi$NE collider, which provides a unique source of monochromatic low-momentum kaons and exploits the KLOE detector as an active target, in order to obtain excellent acceptance and resolution data for $K<sup>-$ nuclear capture on H, ${}<sup>4$He, ${}<sup>{9}$Be and ${}<sup>{12}$C, both at-rest and in-flight. During the second half of 2012 a successful data taking was performed with a dedicated pure carbon target implemented in the central region of KLOE, providing a high statistic sample of pure at-rest $K<sup>-$ nuclear interactions. For the future dedicated setups involving cryogenic gaseous targets are under preparation.