Maximum relative strangeness content in heavy-ion collisions around 30 A GeV

It is shown that the ratio of strange to nonstrange particle production in relativistic heavy-ion collisions is expected to reach a maximum at beam energies around 30 A GeV in the lab frame. This maximum is unique to heavy-ion collisions, and has no equivalent in elementary particle collisions. The appearance of the maximum is due to the energy dependence of the chemical freeze-out parameters and is clearly seen as a pronounced peak in the Wroblewski factor as a function of the incident energy as well as in the behavior of the K+/pi(+) ratio. Below 30 A GeV strange baryons contribute strongly because of the very large value of the chemical potential mu(B). As the energy increases, the decrease of the baryon chemical potential coupled with only moderate increases in the associated temperature causes a decline in the relative number of strange baryons above energies of about 30 AGeV leading to very pronounced maxima in the Lambda/pi(+) and Theta(-)/pi(+) ratios. (C) 2002 Elsevier Science B.V. All rights reserved.