Kaon to Pion ratio in Heavy Ion Collisions

The momentum integrated Boltzmann equation has been used to study the evolution of strangeness of the strongly interacting system formed after the heavy ion collisions at relativistic energies.We argue that the experimentally observed non-monotonic, horn-like structure in the variation of the $K^+/\pi^+$ with colliding energy appears due to the release of large number of colour degrees of freedom.