Near threshold production of the pseudoscalar mesons at the COSY-11 facility

TL;DR

This paper reports on measurements of near-threshold pseudoscalar meson production in proton-proton collisions at COSY-11, revealing differences in meson-nucleon and hyperon-nucleon interaction strengths.

Contribution

It provides new experimental data on meson and hyperon interactions near threshold, highlighting the relative strengths of different meson-nucleon interactions.

Findings

η-proton interaction is significantly stronger than η'-proton

Lambda hyperon interacts more strongly with nucleons than Sigma

K--proton interaction is much stronger than K+-proton

Abstract

We summarise measurements of the COSY-11 collaboration concerning the excitation functions of the near threshold pseudoscalar meson production in the proton-proton interaction. The results are discussed in the context of the meson-nucleon and hyperon-nucleon interactions. We conclude that the $\eta$-proton interaction is significantly stronger than the eta'-proton interaction. Similarly, we found that the hyperon Lambda interacts with the nucleon considerably stronger than the hyperon Sigma, and that the interaction of (K-)-proton is much stronger than this of the (K+)-proton.