Eta physics at threshold

Abstract

The production of eta and eta-prime mesons in elementary nucleon-nucleon collisions has been investigated at the synchrotrons CELSIUS, COSY and SATURNE. The magnitude and energy dependence of the total cross section as well as the occupation distribution of the phase space serve as observables for investigating the mechanisms underlying the production processes and the interaction of mesons with nucleons. The precise data on the eta and eta-prime creation via the pp --> pp eta(eta-prime) reactions allowed to settle the general features of the eta and eta-prime meson production and revealed the sensitivity of the mentioned observables to the nucleon-nucleon-meson final state interaction. The particular production properties, like for example the determination of the dominating exchange processes which lead to the excitation of the S_11 nucleon isobar in the case of eta creation, must be established by confrontation with other observables. The present status of this investigation with an emphasis on the results of the COSY-11 collaboration is briefly presented. The available data are interpreted in view of the production mechanism and the meson-nucleon interaction.

3 pages, 3 figures, Presented at Conference on Quarks and Nuclear Physics (QNP 2002), Julich, Germany, 9-14 Jun 2002

References in corpus (9)

• Close-to-threshold Meson Production in Hadronic Interactions
• S-wave eta'-proton FSI; phenomenological analysis of near-threshold production of pi0, eta, and eta' mesons in proton-proton collisions
• Eta Meson Production in NN Collisions
• The production of eta-mesons in nucleon-nucleon collisions near threshold
• Production of $\eta \prime$ Mesons in the $pp\to pp\eta \prime$ Reaction at 3.67 GeV/c
• eta' meson production in proton-proton collisions
• Analysing power A_y in the reaction p(pol) p --> p p eta close to threshold
• On the Migdal-Watson approach to FSI effects in meson production in NN collisions
• Threshold enhancement in eta photoproduction from 2H and 4He