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RESEARCH PRODUCT

Studies of Hyperons and Antihyperons in Nuclei

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Stored antiproton beams at the international FAIR facility will provide unique opportunities to study hyperons as well as antihyperons in nuclear systems. Precise $\gamma$-spectroscopy of multi-strange hypernuclei will serve as a laboratory for the hyperon-hyperon interaction. Exclusive hadron-antihadron pair production close to threshold can measure the potential of a antihadron relative to that of the coincident hadrons. In the present work we explore the production of excited states in double hypernuclei following the micro-canonical break-up of an initially excited double hypernucleus which is created by the absorption and conversion of a stopped $\Xi^{-}$ hyperon. Generally the formation of excited hypernuclear states relative to ground states dominates in this model. For different initial target nuclei which absorb the $\Xi^-$, different double hypernuclei nuclei dominate. We also compare the model predictions with the correlated pion spectra measured by the E906 collaboration. In antiproton nucleus reactions the event-by-event transverse momentum correlations of hadron-antihadron pairs produced close to threshold contain information on the difference between the nuclear potential of the hadron and the associated antihadron. For produced D-meson pairs at 6.7\gevc1 the sensitivity of the transverse momenta correlation will probably be to small to deduce differences between the potentials for D$^+$ and D$^-$ mesons. However, for {\PgX\PagX} pairs produced at 2.9\gevc1 the asymmetry is sufficiently sensitive to predicted differences between the {\PgX} and {\PagX} potentials even if the momentum and density dependence of the the potential are taken into account.