STRANGENESS EXCITATION FUNCTIONS AND TRANSITION FROM BARYONIC TO MESONIC FREEZE-OUT

The sharp peak in the K+/pi(+) ratio in relativistic heavy-ion collisions is discussed in the framework of the Statistical Model. In this model a rapid change is expected as the hadronic gas undergoes a transition from a baryon-dominated to a meson-dominated gas. The maximum in the Lambda/pi ratio is well reproduced by the Statistical Model, but the change in the K+/pi(+) ratio is so:mewhat less pronounced than the one observed by the NA49 Collaboration. The calculated smooth increase of the K-/pi(-) ratio and the shape of the Xi-/pi(+) and Omega(-)/pi(+) ratios exhibiting maxima at different incident energies is consistent with the presently available experimental data. We conclude that the measured particle ratios with 20-30% deviations agree with a hadronic freeze-out scenario. These deviations seem to occur just in the transition from baryon-dominated to meson-dominated freeze-out.