Signatures of fireball fragmentation at the phase transition

Abstract

It is explained why and how the fireball created in ultrarelativistic nuclear collisions can fragment when passing the phase transition. It can happen at the first-order phase transition but is not excluded even at high collision energies where the smooth crossover is present. Two potential observables sensitive to the appearance of fragmentation are reviewed: event-by-event changes of rapidity distributions and proton correlation in relative rapidity.