Nuclear fragmentation induced by low-energy antiprotons within a microscopic transport approach

TL;DR

This study uses a microscopic transport model to analyze nuclear fragmentation caused by low-energy antiprotons, revealing detailed mechanisms and resulting fragment distributions.

Contribution

It introduces a coalescence approach for primary fragment construction and combines it with statistical decay modeling within the LQMD framework.

Findings

Localized energy from antibaryon-baryon annihilation causes particle emissions and fission.

Strangeness exchange reactions are the main source of hyperons.

Mass loss increases with target nucleus size, with a fission fragment bump in heavy targets.

Abstract

Within the framework of the Lanzhou quantum molecular dynamics (LQMD) transport model, the nuclear fragmentation induced by low-energy antiprotons has been investigated thoroughly. A coalescence approach is developed for constructing the primary fragments in phase space. The secondary decay process of the fragments is described by the well-known statistical code. It is found that the localized energy released in antibaryon-baryon annihilation is deposited in a nucleus mainly via pion-nucleon collisions, which leads to the emissions of pre-equilibrium particles, fission, evaporation of nucleons and light fragments etc. The strangeness exchange reactions dominate the hyperon production. The averaged mass loss increases with the mass number of target nucleus. A bump structure in the domain of intermediate mass for heavy targets appears owing to the contribution of fission fragments.