X-ray spectroscopy of kaonic atoms at SIDDHARTA

¹ Stefan-Meyer-Institut für subatomare Physik, Boltzmanngasse 3, 1090 Wien, Austria
² INFN, Laboratori Nazionali di Frascati, C.P. 13, via E. Fermi 40, 00044 Frascati (Roma), Italy
³ Dep. of Physics and Astronomy, University of Victoria, PO Box 3055, Victoria B.C. Canada V8W3P6
⁴ Politecnico di Milano, Dip. di Elettronica e Informazione, Piazza L. da Vinci 32, 20133 Milano, Italy
⁵ Institutul National pentru Fizica si Inginerie Nucleara Horia Hulubei, Reactorului 30, Magurele, Romania
⁶ INFN Sez. di Roma I and Instituto Superiore di Sanita 00161, Roma, Italy
⁷ University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, Japan
⁸ RIKEN, Institute of Physical and Chemical Research, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
⁹ Excellence Cluster Universe, Tech. Univ. München, Boltzmannstraße 2, 85748 Garching, Germany
¹⁰ Universidade de Santiago de Compostela, Casas Reais 8, 15782 Santiago de Compostela, Spain

^a e-mail: Michael.Cargnelli@oeaw.ac.at

Published online: 9 June 2014

Abstract

The X-ray measurements of kaonic atoms play an important role for understanding the low-energy QCD in the strangeness sector. The SIDDHARTA experiment studied the X-ray transitions of 4 light kaonic atoms (H, D, ³He, and ⁴He) using the DAFNE electron-positron collider at LNF (Italy). Most precise values of the shift and width of the kaonic hydrogen 1s state were determined, which have been now used as fundamental information for the low-energy K⁻p interaction in theoretical studies. An upper limit of the X-ray yield of kaonic deuterium was derived, important for future K⁻d experiments. The shifts and widths of the kaonic ³He and ⁴He 2p states were obtained, confirming the end of the “kaonic helium puzzle”. In this contribution also the plans for new experiments of kaonic deuterium are being presented.