Low Energy Antikaon-nucleon/nuclei interaction studies by AMADEUS

¹ CENTRO FERMI - Museo Storico della Fisica e Centro Studi e Ricerche “Enrico Fermi”, Roma, Italy
² INFN Laboratori Nazionali di Frascati, Frascati, Rome, Italy
³ Politecnico di Milano, Dip. di Elettronica, Informazione e Bioingegneria, Milano, Italy
⁴ Horia Hulubei National Institute of Physics and Nuclear Engineering, Magurele, Romania
⁵ University of Zagreb, Zagreb, Croatia
⁶ INFN Sezione di Milano, Milano, Italy
⁷ Stefan-Meyer-Institut für Subatomare Physik, Wien, Austria
⁸ Università degli Studi di Roma Tor Vergata, Rome, Italy
⁹ Excellence Cluster ‘Origin and Structure of the Universe’, Garching, Germany
¹⁰ Physik Department E12, Technische Universität München, Garching, Germany
¹¹ INFN Sezione di Roma I, Rome, Italy
¹² Istituto Superiore di Sanità, Rome, Italy
¹³ The University of Tokyo, Tokyo, Japan
¹⁴ RIKEN, The Institute of Physics and Chemical Research, Saitama, Japan
¹⁵ Institute of Physics, Jagiellonian University, Kracow, Poland
¹⁶ Departament de Fisica Quantica i Astrofisica and Institut de Ciencies del Cosmos, Universitat de Barcelona, Barcelona, Spain
¹⁷ National Centre for Nuclear Research, Warsaw, Poland

^* e-mail: kristian.piscicchia@lnf.infn.it

Published online: 1 February 2019

Abstract

The AMADEUS experiment at the DAΦNE collider of LNF-INFN deals with the investigation of the at-rest, or low-momentum, K⁻ interactions in light nuclear targets, with the aim to constrain the low energy QCD models in the strangeness sector. The 0 step of the experiment consisted in the reanalysis of the 2004/2005 KLOE data, exploiting K⁻ absorptions in H, ⁴He, ⁹Be and ¹²C, leading to the first invariant mass spectroscopic study with very low momentum (about 100 MeV) in-flight K⁻ captures. With AMADEUS step 1 a dedicated pure Carbon target was implemented in the central region of the KLOE detector, providing a high statistic sample of pure at-rest K⁻ nuclear interaction. The first measurement of the non-resonant transition amplitude $\left|A_{K^{-}n\to \Lambda {\pi }^{-}}\right|$ at $\sqrt{s}=\mathrm{33\hspace{0.17em}}\mathrm{MeV}$ below the K̄N threshold is presented, in relation with the Λ(1405) properties studies. The analysis procedure adopted in the serarch for K⁻ multi-nucleon absorption cross sections and Branching Ratios will be also described.