Exploring the phase space of jet splittings in pp and Pb–Pb collisions with ALICE

We report a series of recent jet substructure measurements made at ALICE, obtained using reclustering techniques. A variety of reclustering algorithms have been employed, with particular emphasis on the Soft Drop grooming procedure. The aim of these analyses are to experimentally access the splittings of the parton shower. Jet shapes are then constructed based on the splitting axes returned by the reclustering algorithms. In pp collisions, these are used to differentially probe fundamental QCD effects and validate PYTHIA at $\sqrt{s} =7$ TeV. In central Pb--Pb collisions at $\sqrt{s_{\rm{NN}}} =2.76$ TeV, these measurements are sensitive to quenching effects in the medium and probe the finer details of the energy loss mechanisms. The measurements presented include the following jet shapes: the ratio of 2-Subjettiness to 1-Subjettiness ($\it{\tau_{2}}/\it{\tau_{1}}$), the opening angle between the two axes of the 2-Subjettiness jet shape ($\Delta R$), the momentum fraction carried by the subleading subjet in the first splitting satisfying Soft Drop ($\it{z}_{g}$) and the number of splittings in the jet tree which fulfil the Soft Drop criterium.