Precision measurement of the 3 d → 2 p x-ray energy in kaonic 4He

S. Okada, G. Beer, H. Bhang, M. Cargnelli, J. Chiba, Seonho Choi, C. Curceanu, Y. Fukuda, T. Hanaki, R. S. Hayano, M. Iio, T. Ishikawa, S. Ishimoto, T. Ishiwatari, K. Itahashi, M. Iwai, M. Iwasaki, B. Juhász, P. Kienle, J. MartonY. Matsuda, H. Ohnishi, H. Outa, M. Sato, P. Schmid, S. Suzuki, T. Suzuki, H. Tatsuno, D. Tomono, E. Widmann, T. Yamazaki, H. Yim, J. Zmeskal

Research output: Contribution to journalArticlepeer-review

93 Citations (Scopus)


We have measured the Balmer-series x-rays of kaonic 4He atoms using novel large-area silicon drift x-ray detectors in order to study the low-energy over(K, ̄)-nucleus strong interaction. The energy of the 3 d → 2 p transition was determined to be 6467 ± 3 (stat) ± 2 (syst)   eV. The resulting strong-interaction energy-level shift is in agreement with theoretical calculations, thus eliminating a long-standing discrepancy between theory and experiment.

Original languageEnglish
Pages (from-to)387-391
Number of pages5
JournalPhysics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
Issue number5-6
Publication statusPublished - 2007 Sep 27
Externally publishedYes


  • Kaonic atom
  • Silicon drift detector
  • X-ray spectroscopy

ASJC Scopus subject areas

  • Nuclear and High Energy Physics


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