We study fluctuations of the sigma field and the net-baryon number on the crossover side of the critical point within the model of nonequilibrium chiral fluid dynamics (N$\chi$FD). Herein, the sigma field as the chiral order parameter is propagated explicitly and coupled to a fluid of quarks. Before investigating these fluctuations in an expanding nonequilibrium medium, we scrutinize the N$\chi$FD model by comparing cumulants of the sigma and net-baryon number fluctuations in a thermalized box to (ratios of) susceptibilities as they are obtained from derivatives of the grand canonical potential. The dynamically determined cumulants follow the trend of the thermodynamic susceptibilities. After implementing a particlization procedure into this model, we study the behavior of the net-proton kurtosis in the critical region and find that it shows the typical shape around the pseudocritical temperature. This demonstrates how critical fluctuations are able to develop in a realistic heavy-ion collision scenario and, moreover, have observable consequences. Finally, we present results for different rapidity windows and transverse momentum cuts.
|Preferred Track||QCD at High Temperature|