Sub-threshold production of $\Sigma$(1385) baryons in Al+Al collisions at 1.9$A$ GeV

Abstract

First measurement of sub-threshold $\Sigma$(1385) production is presented. Experimental data are presented for Al+Al reactions at 1.9$A$ GeV measured with the FOPI detector at SIS/GSI. The $\Sigma$(1385)/$\Lambda$ ratio is found to be in good agreement with the transport and statistical model predictions. The results allow for a better understanding of sub-threshold strangeness production and strangeness exchange reaction which is the dominant process for $K^-$ production below and close-to threshold.