Seminarium Teorii Oddziaływań Elementarnych

The first collisions of lead nuclei, delivered by the CERNLarge Hadron Collider (LHC) at the end of 2010, at a centre-of-massenergy per nucleon pair $\sqrt{s_{NN}} = 2.76$ TeV, marked the beginningof a new era in ultra-relativistic heavy-ion physics. The studyof the properties of the produced hot and dense strongly-interactingmatter at these unprecedented energies is currently experimentallypursued by all four big LHC experiments, ALICE, ATLAS, CMS, and LHCb.In this talk I would present selected experimental results onobservables probing both bulk matter properties as well as hardprocesses in heavy-ion collisions delivered during the first threeyears of the LHC operation. It also presents the first resultsfrom Run 2 heavy-ion data at the highest energy, as well as fromthe studies of the reference pp and pPb systems, which arean integral part of the heavy-ion programme.