Near-threshold production of the multi-strange $Ξ^-$ hyperon

Abstract

The yield for the multi-strange $Ξ^{-}$ hyperon has been measured in 6 AGeV Au+Au collisions via reconstruction of its decay products $π^{-}$ and $Λ$, the latter also being reconstructed from its daughter tracks of $π^{-}$ and p. The measurement is rather close to the threshold for $Ξ^{-}$ production and therefore provides an important test of model predictions. The measured yield for $Ξ^{-}$ and $Λ$ are compared for several centralities. In central collisions the $Ξ^{-}$ yield is found to be in excellent agreement with statistical and transport model predictions, suggesting that multi-strange hadron production approaches chemical equilibrium in high baryon density nuclear matter.

Submitted to PRL