Particle production in antiproton induced nuclear reactions

TL;DR

This paper improves a quantum molecular dynamics model to study antiproton-induced nuclear reactions, analyzing particle production mechanisms and distributions across various nuclei and incident momenta.

Contribution

The study introduces an enhanced model including multiple reaction channels to accurately simulate particle emissions in antiproton collisions with nuclei.

Findings

Model reproduces experimental rapidity and momentum distributions of pions and protons.

Particle production is significantly influenced by antiproton annihilations on nucleons.

Hyperons are mainly produced via meson-induced reactions and strangeness exchange below annihilation threshold.

Abstract

The quantum molecular dynamics model has been improved to investigate the reaction dynamics induced by antiprotons. The reaction channels of elastic scattering, annihilation, charge exchange and inelastic collisions have been included in the model. Dynamics on particle production, in particular pions, kaons, antikaons and hyperons, is investigated in collisions of $\overline{p}$ on $^{12}$C, $^{20}$Ne, $^{40}$Ca, $^{112}$Sn, $^{181}$Ta, $^{197}$Au and $^{238}$U from a low to high incident momentum. The rapidity and momentum distributions of $\pi^{+}$ and protons from the LEAR measurements can be well reproduced. The impacts of system size and incident momentum on particle emissions are investigated from the inclusive spectra, transverse momentum and rapidity distributions. It is found that the annihilations of $\overline{p}$ on nucleons are of importance on the particle production. Hyperons are mainly produced via meson induced reactions on nucleons and strangeness exchange collisions when the incident momentum is below the threshold value of annihilation reaction. A higher nuclear temperature is obtained from the kaon emission, but it has a lower value for hyperon production.