Non-Gaussian Fluctuations near the QCD Critical Point

Abstract

We study the effect of the QCD critical point on non-Gaussian moments (cumulants) of fluctuations of experimental observables in heavy-ion collisions. We find that these moments are very sensitive to the proximity of the critical point, as measured by the magnitude of the correlation length xi. For example, the cubic central moment of multiplicity (deltaN)3 approximately xi4.5 and the quartic cumulant (deltaN)4c approximately xi7. We estimate the magnitude of critical point contributions to non-Gaussian fluctuations of pion and proton multiplicities.