Finite-size scaling and intermittency studies in crucial measurements for the QCD critical point

Abstract

We propose a systematic way to search for the location of the QCD critical point in relativistic ion collisions, based on the relation of intermittency in momentum space to finite-size scaling (FSS) in configuration space. This relation is valid for systems equilibrating within the FSS region. The key ingredients of our method are combined measurements of the intermittency index φ 2 in transverse momentum space of protons produced in central A+A collisions and of the corresponding freeze-out parameters µ b (baryochemical potential) and T (temperature). We demonstrate how the proposed method works in practice using NA49 data for central Si+"Si" collisions at √ s = 17.2 GeV. Based on these data we extract a set of predictions, concerning reachability of the critical endpoint, for the running NA61 experiment at SPS (CERN).