The K/pi horn and the lifetime of the fireball

Boris Tomasik

I will propose a hadronic non-equilibrium model for the description of the excitation function of kaon and lambda multiplicities normalised by pion multiplicities. The key point is that strangeness yield depends not only on the energy density or temperature, but also on the total time of production. I wil demonstrate that the sharp peak in positively charged K/pi can be reproduced if fireball lifetime decreases with increasing beam energy due to weaker stopping.