Differential cross section and analysing power of the pp -> {pp\}_s pi0 reaction at 353 MeV

TL;DR

This paper reports measurements of the differential cross section and analysing power for the pp -> {pp}_s pi^0 reaction at 353 MeV, providing crucial data for understanding pion production mechanisms and partial wave analysis in nucleon-nucleon collisions.

Contribution

It presents new experimental data on the differential cross section and analysing power at a specific energy, enabling detailed partial wave analysis of pion production.

Findings

Data consistent with s- and d-wave pion production models

Unique solutions for production amplitudes obtained using phase information

Results aid in decomposing p-wave contributions in nucleon-nucleon collisions

Abstract

In order to establish links between p-wave pion production in nucleon-nucleon collisions and low energy three-nucleon scattering, an extensive programme of experiments on pion production is currently underway at COSY-ANKE. The final proton pair is detected at very low excitation energy, leading to an S-wave diproton, denoted here as {pp}_s. We now report on measurements of the differential cross section and analysing power of the pol{p}p->{pp}_s pi^0$ reaction at 353 MeV. Both observables can be described in terms of s- and d-wave pion production and, by using the phase information from elastic pp scattering, unique solutions can be obtained for the corresponding amplitudes. This information is vital for the partial wave decomposition of the corresponding pn->{pp}_s pi^- reaction and hence for the extraction of the p-wave terms.