Strangeness production and hypernuclear formation in proton and antiproton induced reactions

TL;DR

This study systematically investigates strangeness production and hypernuclear formation in proton and antiproton induced reactions using a microscopic transport model, highlighting the effects of hyperon-nucleon interactions and energy dependence.

Contribution

It introduces a comprehensive model combining hyperfragment formation and decay processes, providing new insights into hypernuclear yields in antiproton and proton collisions.

Findings

Hyperon-nucleon interaction has negligible effect on free hyperon production.

Large hyperfragment yields are observed with attractive potentials.

Double strangeness hyperfragment production is significantly lower than single hyperfragments.

Abstract

Strange particles and hyperfragments in collisions of antiprotons and protons on nuclei have been investigated systematically within a microscopic transport model. The hyperons are produced from the annihilation in antibaryon-baryon collisions and strangeness exchange process in antiproton induced reactions. A coalescence approach is used for constructing the primary hyperfragments in phase space and the statistical model is modified for describing the decay of hyperfragments via evaporating hyperon, neutron, charged particles etc, in which the shell effect, binding energy and root-mean-square radii are taken into account. It is found that the influence of the hyperon-nucleon interaction on the free $\Lambda$ and $\Xi^{-}$ production is negligible. However, the large hyperfragment yields are obvious with the attractive potential. The production of double strangeness hyperfragments are reduced below 1$\mu b$ in comparison to the yields of $\Lambda$-hyperfragments with the cross sections of 0.05-0.1 mb in the antiproton induced reactions on $^{63}$Cu at the incident momenta of 1-5 GeV/c. The light hyperfragments are formed in the dynamical fragmentation process. The energy dependence of hyperfragment formation is weak once the incident energy above the threshold energy for the hyperon production.