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Observation of πK-atoms with DIRAC-II

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Abstract

We present evidence for the first observation of electromagnetically bound π ± K  ∓ -pairs (πK-atoms) with the DIRAC-II experiment at the CERN-PS. The πK-atoms are produced by the 24 GeV/c proton beam in a thin Pt-target and the dissociated π ± and K  ∓ -mesons analyzed in a two-arm magnetic spectrometer. The observed enhancement at low relative momentum corresponds to the production of 173±54 πK-atoms. The mean life of πK-atoms is related to the s-wave πK-scattering lengths. From these first data we derive a lower limit for the mean life of 1.5 fs at 84% confidence level.

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  1. University of Zurich, 8057, Zürich, Switzerland

    Y. Allkofer

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  1. Y. Allkofer
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(on behalf of the DIRAC-II collaboration)

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Correspondence to Y. Allkofer.

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Allkofer, Y., (on behalf of the DIRAC-II collaboration). Observation of πK-atoms with DIRAC-II. Hyperfine Interact 193, 39–45 (2009). https://doi.org/10.1007/s10751-009-0067-9

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