New precision era of experiments on strong interaction with strangeness at DAFNE/LNF-INFN

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, I-00044 Frascati ( Roma), Italy
³ Department of Physics and Astronomy, University of Victoria, P.O. Box 1700 STN CNC, Victoria BC V8W 2Y2, Canada
⁴ Politecnico di Milano, Dipartimento di Elettronica e Informazione, Piazza L. da Vinci 32, I-20133 Milano, Italy
⁵ IFIN-HH, Institutul National pentru Fizica si Inginerie Nucleara Horia Hulubei, Reactorului 30, Magurele, Romania
⁶ INFN Sezione di Roma I and Instituto Superiore di Sanita, I-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, Technische Universität München, Boltzmannstraße 2, D-85748 Garching, Germany
¹⁰ Universidade de Santiago de Compostela, Casas Reais 8, 15782 Santiago de Compostela, Spain

^a e-mail: tomoichi.ishiwatari@assoc.oeaw.ac.at

Published online: 20 March 2014

Abstract

The strong-interaction shifts and widths of kaonic hydrogen, deuterium, ³He, and ⁴He were measured in the SIDDHARTA experiment. The most precise values of the shift and width of the kaonic hydrogen 1s state were determined to be ϵ_1s = −283 ± 36(stat)±6(syst) eV and Γ_1s = 541±89(stat)±22(syst) eV. The upper limit of the kaonic deuterium Kα yield was found to be ≤ 0.39%. In addition, the shifts and widths of the kaonic ³He and ⁴He 2p states were determined to be ϵ_2p(³He) = −2 ± 2(stat) ± 4(syst) eV and Γ_2p(³He) = 6 ± 6(stat) ± 7(syst) eV; ϵ_2p(⁴He) = +5 ± 3(stat) ± 4(syst) eV and Γ_2p(⁴He) = 14 ± 8(stat) ± 5(syst) eV. These values are important for the constraints of the low-energy $\overline{K}N$ interaction in theoretical approaches.