The Impact of the Fragmentation Processes of Spectators on the Centrality Determination in Heavy-Ion Collisions

A heavy-ion collision experiment has a wide range of physical observables that are dependent on the initial geometry. Centrality is used to describe the initial geometry of collisions in experiments. Spectator fragments, or pieces of the colliding nuclei that were not involved in the collision, can be used to determine centrality. In this work, we discuss how processes of spectator fragmentation may impact the centrality determination procedure. These effects are demonstrated using the DCM-QGSM-SMM model, which realistically reproduces fragmentation processes, and the published results of the NA61/SHINE experiment.