Abstract
This contribution reports on the results obtained in the two recently published papers [A. Bialas, A. Bzdak, K. Zalewski, Phys. Lett. B710, 332 (2012); A. Bialas, K. Zalewski, Acta Phys. Pol. B 43, 1357 (2012)] demonstrating that data of the STAR Collaboration show a substantial asymmetric component in the rapidity distribution of the system created in central Au-Au collisions, implying that boost invariance is violated on the event-by-event basis even at the mid c.m. rapidity.
