Hypernuclei, dibaryon and antinuclei production in high energy heavy ion collisions: Thermal production vs. Coalescence

Abstract

We study the production of (hyper-)nuclei and di-baryons in most central heavy Ion collisions at energies of $E_{lab}=1-160 A$ GeV. In particular we are interested in clusters produced from the hot and dense fireball. The formation rate of strange and non-strange clusters is estimated by assuming thermal production from the intermediate phase of the UrQMD-hydro hybrid model and alternatively by the coalescence mechanism from a hadronic cascade model. Both model types are compared in detail. For most energies we find that both approaches agree in their predictions for the yields of the clusters. Only for very low beam energies, and for di-baryons including $\Xi$'s, we observe considerable differences. We also study the production of anti-matter clusters up to top RHIC energies and show that the observation of anti-$^4He$ and even anti-$^4_{\Lambda}He$ is feasible. We have found a considerable qualitative difference in the energy dependence of the strangeness population factor $R_H$ when comparing the thermal production with the coalescence results.