Event shape engineering with ALICE

The strong fluctuations in the initial energy density of heavy-ion collisions allow an efficient selection of events corresponding to a specific initial geometry. For such “shape engineered events”, the elliptic flow coefficient, image, of unidentified charged particles, pions and (anti-)protons in Pb–Pb collisions at image is measured by the ALICE collaboration. image obtained with the event plane method at mid-rapidity, image, is reported for different collision centralities as a function of transverse momentum, image, out to image. The measured image for the shape engineered events is significantly larger or smaller than the average which demonstrates the ability to experimentally select events with the desired shape of the initial spatial asymmetry.