1. Evidence for $\pi K$-atoms with DIRAC
- Author
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Adeva, B., Afanasyev, L., Allkofer, Y., Amsler, C., Anania, A., Benelli, A., Brekhovskikh, V., Caragheorgheopol, G., Cechak, T., Chiba, M., Chliapnikov, P., Ciocarlan, C., Constantinescu, S., Curceanu, C., Detraz, C., Dreossi, D., Drijard, D., Dudarev, A., Duma, M., Dumitriu, D., Fungueiriño, J. L., Gerndt, J., Gorin, A., Gorchakov, O., Gritsay, K., Guaraldo, C., Gugiu, M., Hansroul, M., Hons, Z., Horikawa, S., Iliescu, M., Karpukhin, V., Kluson, J., Kobayashi, M., Komarov, V., Kruglov, V., Kruglova, L., Kulikov, A., Kuptsov, A., Kurochkin, I., Lamberto, A., Lanaro, A., Lapshin, V., Lednicky, R., Sandri, P. Levi, Aguera, A. Lopez, Lucherini, V., Manuilov, I., Mariñas, C., Nemenov, L., Nikitin, M., Okada, K., Olchevskii, V., Pentia, M., Penzo, A., Pló, M., Rappazzo, G. F., Regenfus, C., Rochet, J., Romero, A., Ronjin, V., Ryazantsev, A., Rykalin, V., Saborido, J., Schacher, J., Sidorov, A., Smolik, J., Sugimoto, S., Takeutchi, F., Tarasov, A., Tauscher, L., Trojek, T., Trusov, S., Utkin, V., Doce, O. Vázquez, Vrba, T., Yazkov, V., Yoshimura, Y., Zhabitsky, M., and Zrelov, P.
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High Energy Physics - Experiment - Abstract
We present evidence for the first observation of electromagnetically bound $\pi^\pm K^\mp$-pairs ($\pi K$-atoms) with the DIRAC experiment at the CERN-PS. The $\pi K$-atoms are produced by the 24 GeV/c proton beam in a thin Pt-target and the $\pi^\pm$ and $K^\mp$-mesons from the atom dissociation are analyzed in a two-arm magnetic spectrometer. The observed enhancement at low relative momentum corresponds to the production of 173 $\pm$ 54 $\pi K$-atoms. The mean life of $\pi K$-atoms is related to the s-wave $\pi K$-scattering lengths, the measurement of which is the goal of the experiment. From these first data we derive a lower limit for the mean life of 0.8 fs at 90% confidence level., Comment: 15 pages, 9 figures
- Published
- 2009
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