Kaonic hydrogen X-ray measurement in SIDDHARTA

• Published in: Nuclear physics. A 2012-05, Vol.881, p.88-97
• Main Authors: Bazzi, M., Beer, G., Bombelli, L., Bragadireanu, A.M., Cargnelli, M., Corradi, G., Curceanu (Petrascu), C., dʼUffizi, A., Fiorini, C., Frizzi, T., Ghio, F., Guaraldo, C., Hayano, R.S., Iliescu, M., Ishiwatari, T., Iwasaki, M., Kienle, P., Levi Sandri, P., Longoni, A., Lucherini, V., Marton, J., Okada, S., Pietreanu, D., Ponta, T., Rizzo, A., Romero Vidal, A., Scordo, A., Shi, H., Sirghi, D.L., Sirghi, F., Tatsuno, H., Tudorache, A., Tudorache, V., Vazquez Doce, O., Widmann, E., Zmeskal, J.
• Format: Article
• Language: English
• Subjects: Antikaon–nucleon physics; Kaonic atoms; Low-energy QCD; X-ray detection
• ISSN: 0375-9474
• DOI: 10.1016/j.nuclphysa.2011.12.008

Kaonic hydrogen atoms provide a unique laboratory to probe the kaon–nucleon strong interaction at the energy threshold, allowing an investigation of the interplay between spontaneous and explicit chiral symmetry breaking in low-energy QCD. The SIDDHARTA Collaboration has measured the K-series X rays of kaonic hydrogen atoms at the DAΦNE electron–positron collider of Laboratori Nazionali di Frascati, and has determined the most precise values of the strong-interaction induced shift and width of the 1s atomic energy level. This result provides vital constraints on the theoretical description of the low-energy K¯N interaction.