Improved intermittency analysis of proton density fluctuations in NA49 ion collisions at 158 AGeV

The existence of the QCD critical point is a controversial issue, which is expected to be clarified in current ion collision experiments. In the vicinity of the critical point, according to recent theoretical investigations, the chiral condensate (chiral order parameter) should exhibit critical fluctuations (self-similarity and scale-invariance). These fluctuations should also be present in the transverse momentum distributions of protons produced in ion collision experiments due to the coupling of the chiral condensate with the net-proton density.