Production of fragments and hyperfragments in antiproton-nucleus collisions

TL;DR

This paper investigates the formation of strange fragments and hyperfragments in antiproton-nucleus collisions using a combined transport and statistical decay model, highlighting the production of heavier hyperfragments with strangeness.

Contribution

It introduces a coalescence approach within the LQMD framework to model hyperfragment formation, including decays, in antiproton-induced reactions, emphasizing the production of hypernuclei with multiple strangeness.

Findings

Hyperfragments are produced at narrower rapidities and lower kinetic energies.

The combined model effectively describes fragment production in low-energy antiproton reactions.

Heavy hyperfragments with strangeness s=-2 and s=1 are preferentially formed.

Abstract

Formation mechanism of fragments with strangeness in collisions of antiprotons on nuclei has been investigated within the Lanzhou quantum molecular dynamics (LQMD) transport approach combined with a statistical model (GEMINI) for describing the decays of excited fragments. Production of strange particles in the antiproton induced nuclear reactions is modeled within the LQMD model, in which all possible reaction channels such as elastic scattering, annihilation, charge exchange and inelastic scattering in antibaryon-baryon, baryon-baryon and meson-baryon collisions have been included. A coalescence approach is developed for constructing hyperfragments in phase space after de-excitation of nucleonic fragments. The combined approach could describe the production of fragments in low-energy antiproton induced reactions. Hyperfragments are formed within the narrower rapidities and lower kinetic energies. It has advantage to produce heavier hyperfragments and hypernuclides with strangeness s=-2 (double-$\Lambda$ fragments) and s=1 ($\overline{\Lambda}$-fragments) in antiproton induced reactions.