0000000000204626
AUTHOR
H. Funahashi
Measurement of single spin asymmetry in η-meson production in p↑p and p̄↑p interactions in the beam fragmentation region at 200 GeV/c
We present experimental results on measuring a single spin asymmetry in η-meson production in the interaction of transversely polarized protons and antiprotons at plab = 200 GeV/c with a proton target in the region 0.2 < xF < 0.7 for p↑p, 0.3 < xF < 0.7 for p↑p and 0.7 < pT < 2.0 GeV/c. A comparison of single spin asymmetries in π- and η-meson production is made.
EXTRACTION OF ΛΛ SCATTERING LENGTH
We determine ΛΛ scattering parameters from a ΛΛ invariant mass spectrum that was obtained by 12 C (K-, K+ΛΛ) reaction at the KEK Proton Synchrotron. In the framework of Watson's procedure, the obtained scattering length [Formula: see text] and effective range [Formula: see text] are most consistent with the values predicted by using the Nijmegen soft core models (NSC97's). However, the predicted values by using the Nijmegen hard-core ND ( G -matrix) and the extended soft-core (ESC00) models are out of two standard deviations from the determined scattering parameters.