Kaonic ³He and ⁴He measurements in the SIDDHARTA experiment at the DAΦNE collider

¹ INFN, Laboratori Nazionali di Frascati, Frascati (Roma), Italy
² Department of Physics and Astronomy, University of Victoria, Victoria, BC, Canada
³ Politecnico di Milano, Sezione di Elettronica, Milano, Italy
⁴ Horia Hulubei National Institute of Physics and Nuclear Engineering, Magurele, Romania
⁵ Stefan-Meyer-Institut für subatomare Physik, Vienna, Austria
⁶ INFN Sezione di Roma I and Istituto Superiore di Sanità, Roma, Italy
⁷ The University of Tokyo, Tokyo, Japan
⁸ RIKEN, The Institute of Physics and Chemical Research, Saitama, Japan
⁹ Technische Universität München, Physik Department, Garching, Germany
¹⁰ University of Santiago de Compostela, Santiago de Compostela, Spain

^a e-mail: hideyuki.tatsuno@lnf.infn.it

Abstract

The SIDDHARTA collaboration measured kaonic ³He and ⁴He 3d → 2p X-rays with gaseous targets at the DAΦNE e⁺e⁻ collider. The 2p-state strong-interaction shifts and widths were precisely determined by using 144 high-resolution silicon drift detectors. The shift of K⁻⁴He is in good agreement with theoretical calculations and consistent with the recent experimental result of KEK-PS E570. The shift of K⁻³He is also determined for the first time. The newly determined widths are in agreement with optical model calculations.