arXiv subjects
Publications and source records attributed to A. M. Gasparian.
A model calculation for the reactions $pp\to pΛK^+$ and $pp\to NΣK$ near their thresholds is presented. It is argued that the experimentally observed strong suppression of $Σ^0$ production compared to $Λ$ production at the same excess energy could be due to a destructive interference between the $π$ and $K$ exchange contributions in the reaction $pp\to pΣ^0 K^+$. Predictions for $pp\to pΣ^+ K^0$ and $pp\to nΣ^+ K^+$ are given.
The influence of the nucleon-nucleon final state interaction (FSI) on properties of the meson production amplitude near threshold is discussed. For the nucleon-nucleon interaction a simple Yamaguchi potential as well as realistic potential models are considered. It is shown that FSI effects cannot be factorized from the production amplitude. The absolute magnitude of FSI effects depends on the momentum transfer (or on the mass of the produced meson) and hence is not universal. Only in the case of the production of rather heavy mesons like eta' or phi FSI effects become universal. The Jost function approach to FSI effects is critically examined.