Measurement of the invariant mass distributions for the pp -> ppeta' reaction at excess energy of Q = 16.4 MeV

TL;DR

This study measured the invariant mass distributions for the pp -> ppeta' reaction at 16.4 MeV excess energy, revealing shape similarities to the pp -> ppeta reaction and excluding proton-eta' interaction as the cause of observed enhancements.

Contribution

First measurement of the invariant mass distributions for the pp -> ppeta' reaction at this energy, providing insights into proton-meson interactions.

Findings

Invariant mass distributions are similar to those of the pp -> ppeta reaction.

Enhancement observed at large proton-proton relative momenta.

Proton-eta' interaction is weaker than proton-eta interaction, explaining the enhancement.

Abstract

The proton-proton and proton-eta' invariant mass distributions have been determined for the pp -> ppeta' reaction at an excess energy of Q = 16.4 MeV. The measurement was carried out using the COSY-11 detector setup and the proton beam of the cooler synchrotron COSY. The shapes of the determined invariant mass distributions are similar to those of the pp -> ppeta reaction and reveal an enhancement for large relative proton-proton momenta. This result, together with the fact that the proton-eta interaction is much stronger that the proton-eta' interaction, excludes the hypothesis that the observed enhancement is caused by the interaction between the proton and the meson.