Kaonic helium-4 X-ray measurement in SIDDHARTA

• DOI: 10.1016/j.physletb.2009.10.052
• Publication Date: 2009-10-22T12:58:40Z
• Authors: M. Bazzi; G. Beer; L. Bombelli; A.M. Bragadireanu; M. Cargnelli; G. Corradi; C. Curceanu (Petr...; A. d'Uffizi; C. Fiorini; T. Frizzi; F. Ghio; B. Girolami; C. Guaraldo; R.S. Hayano; M. Iliescu; T. Ishiwatari; M. Iwasaki; P. Kienle; P. Levi Sandri; A. Longoni; V. Lucherini; J. Marton; S. Okada; D. Pietreanu; T. Ponta; A. Rizzo; A. Romero Vidal; A. Scordo; H. Shi; D.L. Sirghi; F. Sirghi; H. Tatsuno; A. Tudorache; V. Tudorache; O. Vazquez Doce; E. Widmann; J. Zmeskal
• Keywords: 0103 physical sciences; 01 natural sciences; 7. Clean energy

Abstract The kaonic helium-4 3 d → 2 p X-ray transition was measured in a gaseous target, where Compton scattering in helium is negligible. The X-rays were detected with large-area Silicon Drift Detectors (SDDs) using the timing information of the K + K − pairs produced by ϕ decays at the DAΦNE e + e − collider. A new value of the strong interaction shift of the kaonic 4He 2p state was determined to be 0 ± 6 (stat) ± 2 (syst) eV , which confirms the recently obtained result by the KEK-PS E570 group.