K. Kilian

Production of antihydrogen

Results are presented for a measurement for the production of the antihydrogen atom H0 ≡ pe+, the simplest atomic bound state of antimatter. A method has been used by the PS210 collaboration at LEAR which assumes that the production of H0 is predominantly mediated by the e+e−-pair creation via the two-photon mechanism in the antiproton-nucleus interaction. Neutral H0 atoms are identified by a unique sequence of characteristics. In principle H0 is well suited for investigations of fundamental CPT violation studies under different forces, however, in our investigations we concentrate on the production of this antimatter object, since so far it has never been observed before. The production of 11 antihydrogen atoms is reported including possibly 2±1 background signals, the observed yield agrees with theoretical predictions.

COSY- 11, an internal experimental facility for threshold measurements

Abstract The COSY-11 installation is an internal experiment at the cooler synchrotron and storage ring COSY Julich. It has been designed for full geometrical acceptance close to threshold for meson production studies, especially in the 1 GeV/ c 2 mass range. The experimental setup makes use of a regular C-type COSY dipole magnet, following a cluster target, to separate reaction products from the beam and to analyze their momenta, thus allowing the observation of charged reaction products at small angles with beam energies close to threshold. Resonances will be identified by missing mass reconstructions from measured four-momenta of two outgoing protons in the predominantly studied pp → ppX reaction. In addition, charged mesons either produced directly or from decays of X will be detected. The different components of the experimental facility are presented.

The pp → ppπ0 reaction near the kinematical threshold

The pp → ppη reaction has been measured at six energies close to threshold, from 1258 MeV to 1352 MeV, using an internal cluster gas jet target in the CELSIUS storage ring. The η is detected through its decay photons, in an array of CsI detectors, and the forward-going protons are detected in a plastic scintillator spectrometer. A complete event reconstruction is obtained at the higher energies in the measured interval. The new data, together with earlier data, give an accurate determination of the energy dependence close to threshold. The influence of the η-proton FSI is seen in the total cross section data as well as in a Dalitz plot of the η-p invariant mass distributions.

The WASA Detector Facility at CELSIUS

The WASA 4 pi multidetector system, aimed at investigating light meson production in light ion collisions and eta meson rare decays at the CELSIUS storage ring in Uppsala is presented. A unique fea ...

Production of ω mesons in proton–proton collisions

The cross section for the production of

Detector setup for a storage ring with an internal target

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Experimental study of pp eta dynamics in the pp ---> pp eta reaction

mesons in proton-proton collisions has been measured in a previously unexplored region of incident energies. Cross sections were extracted at 92 MeV and 173 MeV excess energy, respectively. The angular distribution of the

Measurement of the eta production in proton proton collisions with the COSY time-of-flight spectrometer

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A three layer circular scintillator hodoscope

at

A liquid hydrogen/deuterium target with very thin windows

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