prof. dr hab. Andrzej Białas (Instytut Fizyki Jądrowej PAN, Kraków)

Hidden asymmetry in symmetric collisions

Interpretation of long-range rapidity correlations in terms of the rapidity density distribution of the system created in high-energy collisions is proposed. When applied to recent data of the STAR coll., it shows a substantial asymmetric component in the shape of the system produced in central Au-Au collisions, implying that boost invariance is violated on the event-by-event basis {it even} at central rapidity. This observation may substantially modify evaluations of the hydrodynamic expansion of the system.