Net-baryon number variance and kurtosis within nonequilibrium chiral fluid dynamics

Abstract

We study the variance and kurtosis of the net-baryon number in a fluid dynamical model for heavy-ion collisions. It is based on an effective chiral model with dilatons for the strong coupling regime of QCD. Taking into account spinodal instabilities, we demonstrate that this model exhibits a diverging quark number susceptibility and kurtosis all along the spinodal lines of the first-order phase transition, with a change of universality class at the critical end point. During the (3+1) dimensional expansion of a hot and dense fireball, instabilities are created by fluctuations in the explicitly propagated chiral and dilaton field. We find a clear enhancement of event-by-event fluctuations of the baryon number at the critical point and first-order phase transition in comparison with an evolution through the crossover region.

15 pages, 5 figures

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Cited by in corpus (8)

• Effects of global charge conservation on time evolution of cumulants of conserved charges in relativistic heavy ion collisions
• Dynamics of critical fluctuations: Theory -- phenomenology -- heavy-ion collisions
• Enhanced pion-to-proton ratio at the onset of the QCD phase transition
• Role of slow, out-of-equilibrium modes on the dynamic structure factor near the QCD critical point
• Net-proton number cumulant ratios as function of beam energy from an expanding nonequilibrium chiral fluid
• Dynamics of the conserved net-baryon density near QCD critical point within inhomogeneous quark-gluon plasma profile
• Multiplicity fluctuations at the quark-hadron phase transition from a fluid dynamical model
• Cumulants of the chiral order parameter at lower RHIC energies