Emergence of New Systematics for Open Charm Production in High Energy Collisions

We present the production systematics of open charm hadron yields in high-energy collisions and their description based on the Statistical Hadronization Model. The rapidity density of D⁰, D⁺, D*+, Dₛ⁺ mesons and Λc⁺ baryons in heavy ion and proton-proton collisions is analyzed for different collision energies and centralities. The Statistical Hadronization Model is extended to open charm production in minimum-bias and high-multiplicity pp collisions. In this context, we use the link established in [1], see also the further development in [2], between the rapidity density of open charm hadron yields, dNᵢ/dy, and the rapidity density of charm-anticharm quark pairs, dNc c/dη to demonstrate that, in pp, pA and AA collisions, dNᵢ/dy scales in leading order with dNc c/dη and the slope coefficient is quantified by the appropriate thermal density ratio calculated at the chiral crossover temperature, Tc=156.5 MeV. It is also shown that, in high energy collisions and within uncertainties, dNᵢ/dy exhibits the power-law scaling with the charged-particle pseudo-rapidity density. Furthermore, presently available data on different ratios of open charm rapidity densities in high-energy collisions are independent of collision energy and system size, as expected in the Statistical Hadronization Model.