Near-threshold Production of Η-mesons
نویسنده
چکیده
It is shown that the striking energy variation in the p d → 3He η cross section near threshold is probably due to a final state interaction associated with a large (complex) η − 3He scattering length. The consequences of this hypothesis are studied for the production of the meson in the η − 4He and η − 7Be channels. PACS number(s): 25.40.Ve, 13.75.-n, 25.10.+s The cross sections for the production of η and π mesons via the p d → He η and p d → He π reactions behave very differently close to their respective thresholds. Taking out the kinematic factor of the ratio of the outgoing to the incident centre-of-mass momenta, we can define an average squared amplitude through |fη(π)| 2 = pp pη(π) (
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