Model-independent tracking of criticality signals in nuclear multifragmentation date

We study multifragment production in central heavy-ion collisions using model-independent universal fluctuations theory and a wide range of INDRA data for central collisions of symmetric systems of total mass A: 75 - 400 at bombarding energies from 25 to 100 MeV/nucleon. We find evidence for two different regimes at low and high incident energies, respectively, defined by the fluctuation scaling properties of the largest fragment in each event, Z(max), which plays the role of an order parameter. Data for a wide range of system masses and incident energies collapse on to an approximately universal scaling function in each regime. The form of the scaling functions is established, and their dependence on total system mass and bombarding energy is mapped out. (authors)