Toward Initial Conditions of Conserved Charges Part II: The ICCING Monte Carlo Algorithm

Mauricio Martinez, Matthew D. Sievert, Douglas E. Wertepny, and Jacquelyn Noronha-Hostler

1911.12454

Comparison of the event geometry which is responsible for bulk particle production, versus initial strangeness production. The significant mass threshold of the strange quarks leads to them being produced only at hot spots, rather than throughout the fireball. As such, they provide access to wholly new information about the initial state than bulk observables.

At top collider energies where μB≈0, the initial stages of heavy ion collisions are dominated by small-xx gluons. While the sea quarks obtained perturbatively by g → q qbar pair production from these gluons constitute a minority of the initial energy, they are still present in significant numbers. Crucially, these sea quarks carry conserved charges which the gluons do not: baryon number, strangeness, and electric charge. Even though the total charges of the initial state are zero, their spatial fluctuations about zero permit the study of charge diffusion physics in the quark-gluon plasma (QGP) even at top collider energies. In this paper we present a new model denoted ICCING (Initial Conserved Charges in Nuclear Geometry) for reconstructing the initial conditions of conserved charges in the QGP by sampling the g → q qbar splitting function over the initial energy density. In this way, we provide a new numerical tool which can supplement any model of the initial energy density with the associated conserved charges. The new information provided by these conserved charges opens the door to a wealth of new charge- and flavor-dependent correlations in the initial state which can reveal new transport parameters of the QGP.