Invariant mass distributions for the pp to p p eta reaction at Q=10 MeV

TL;DR

This study measures invariant mass distributions and total cross sections for the pp to pp eta reaction at Q=10 MeV, revealing low-momentum enhancements similar to higher energies, using the COSY-11 detector.

Contribution

First measurement of invariant mass distributions at Q=10 MeV for the pp to pp eta reaction with detailed analysis of low-momentum enhancements.

Findings

Significant low proton-proton relative momentum enhancement observed.

Invariant mass spectra consistent with previous higher-energy measurements.

Total cross section determined near threshold.

Abstract

Proton-proton and proton-eta invariant mass distributions and the total cross section for the pp to pp eta reaction have been determined near the threshold at an excess energy of Q=10 MeV. The experiment has been conducted using the COSY-11 detector setup and the cooler synchrotron COSY. The determined invariant mass spectra reveal significant enhancements in the region of low proton-proton relative momenta, similarly as observed previously at higher excess energies of Q=15.5 MeV and Q= 40MeV.