Baryon fluctuation signatures of the onset of deconfinement

Abstract

An anomalous collision-energy dependence of proton number fluctuations is predicted as a consequence of the onset of deconfinement in heavy-ion collisions at the center of mass energy of the nucleon pair of about 10 GeV. The effect arises from changes in the effective degrees of freedom between confined and deconfined matter. This may provide a natural explanation of the recent beam-energy-scan results on proton number fluctuations at the BNL RHIC and offers a consistent interpretation of data from the CERN SPS and RHIC experiments in terms of the onset of deconfinement.