Beam energy and centrality dependence of the multiplicity fluctuations in heavy ion collisions

Event-by-event fluctuations of thermodynamic quantities have been proposed as the basic tools for understanding the particle production mechanisms and to probe the QCD phase transition. The fluctuations of experimentally accessible quantities, such as particle multiplicities, mean transverse momenta, temperature, particle ratios, and other global observables are related to the thermodynamic properties of the system, such as the entropy, specific heat, chemical potential and matter compressibility. A non-monotonic behaviour of multiplicity fluctuations may signal the onset of deconfinement and can be effectively used to probe the critical point in the QCD phase diagram. Measurements at the vanishing μB at LHC energies set the scale of all theoretical calculations, and one can accurately calculate several quantities and their fluctuations