Universal scaling of the sigma field and net-protons from Langevin dynamics of model A

Abstract

In this paper, we investigate the Kibble-Zurek scaling of the sigma field and net-protons within the framework of Langevin dynamics of model A. After determining the characteristic scales $\tau_{kz},l_{kz}$ and $\theta_{kz}$ and properly rescaling the traditional cumulants, we construct universal functions for the sigma field and approximate universal functions for net-protons in the critical regime, which are insensitive to the relaxation time and the chosen evolving trajectory. Besides, the oscillating behavior for the higher order cumulants of net-protons near the critical point is also drastically suppressed, which converge into approximate universal curves with these constructed Kibble-Zurek functions.