The strangeness production in heavy ion collisions was proposed to be probes of the nuclear equation of state, Kaon potential in nuclear medium, strange quark matter and quark-gluon plasma, etc. However, to act as reliable probes, proper understanding of the basic ingredients for the strangeness production, such as pp → pK+Λ, pp → ppϕ and pp → nK+Σ+ is necessary. Recent study of these reactions clearly shows that previously ignored contributions from the spin-parity 1/2- resonances, N*(1535) and Δ*(1620), are in fact very important for these reactions, especially for near-threshold energies. It is necessary to include these contributions for getting reliable calculation for the strangeness production in heavy ion collisions.
Dynamics of strangeness production in heavy-ion collisions near threshold energies