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We present evidence for the rst observation of electromagnetically bound π ± K ∓pairs (πK-atoms) with the DIRAC experiment at the CERN-PS. The πK-atoms are produced by the 24 GeV/c proton beam in a thin Pt-target and the π ± and K ∓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 ± 54 πK-atoms. The mean life of πK-atoms is related to the s-wave πKscattering lengths, the measurement of which is the goal of the experiment. From these rst data we derive a lower limit for the mean life of 0.8 fs at 90% condence level.

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Based on single ended strip structure, symmetric, multi gap RPC, developed by us more than a decade ago, the time-of-flight barrel of FOPI experiment at GSI-Darmstadt was designed, constructed and is currently in operation. Motivated by the requirements of the next generation experiments in terms of very good time resolution in high counting rate and multiplicity environment, a new architecture of differential, strip structure, symmetric, multi gap timing RPC was developed. The results on efficiency, two dimensions position resolution, time resolution and performance in high counting rate environment using low resistivity glass electrodes are reported.