Comparative studies of the interaction in the low energy ppeta and ppeta' systems

TL;DR

This study compares the interactions in low-energy proton-proton-eta and proton-proton-eta' systems by analyzing differential distributions and cross sections, providing insights into meson-proton interactions and testing theoretical models.

Contribution

It presents detailed experimental data on pp -> ppeta' reactions and compares these with pp -> ppeta data to evaluate meson-proton interaction hypotheses and theoretical models.

Findings

Invariant mass distributions do not support strong meson-proton interaction effects.

Results challenge existing theoretical models for meson production.

Comparison suggests similar interaction dynamics for eta and eta' production.

Abstract

The COSY-11 collaboration measured the pp -> ppeta and pp -> ppeta' reactions in order to perform comparative studies of the interactions within the proton-proton-meson system. This thesis presents in detail the analysis of the pp -> ppeta' reaction which was measured at the proton beam momentum of 3.260 GeV/c. The elaboration results in differential distributions of squared invariant proton-proton (s_pp) and proton-eta' (s_peta') masses, as well as in angular distributions and the total cross section at an excess energy of 16.4 MeV. The differential distributions s_pp and s_peta' are compared to theoretical predictions and to the analogous spectra determined for the pp -> ppeta reaction. The comparison of the results for the eta and eta' meson production rather excludes the hypothesis that the enhancement observed in the invariant mass distributions is due to the meson-proton interaction. Further, the shapes of the distributions do not favour any of the postulated theoretical models.