Higher Order Cumulants in Colorless Partonic Plasma

TL;DR

This paper introduces a novel finite-size cumulant expansion method to identify the QCD deconfinement transition point in finite volume systems, revealing oscillatory behaviors in higher order cumulants as sensitive indicators.

Contribution

It develops a new approach using finite-size cumulant expansion and the $\\mathscr{L}_{m,n}$-Method to locate the QCD deconfinement transition in finite volume.

Findings

Higher order cumulants exhibit pronounced oscillations near the transition.

Sign structure of cumulants can serve as a sensitive probe of the phase transition.

Finite volume transition point correlates with specific features in cumulants.

Abstract

Any physical system considered to study the QCD deconfinement phase transition certainly has a finite volume, so the finite size effects are inevitably present. This renders the location of the phase transition and the determination of its order as an extremely difficult task, even in the simplest known cases. In order to identify and locate the colorless QCD deconfinement transition point in finite volume $T_{0}(V)$, a new approach based on the finite-size cumulant expansion of the order parameter and the $\mathscr{L}_{m,n}$-Method is used.We have shown that both cumulants of higher order and their ratios, associated to the thermodynamical fluctuations of the order parameter, in QCD deconfinement phase transition behave in a particular enough way revealing pronounced oscillations in the transition region. The sign structure and the oscillatory behavior of these in the vicinity of the deconfinement phase transition point might be a sensitive probe and may allow one to elucidate their relation to the QCD phase transition point. In the context of our model, we have shown that the finite volume transition point is always associated to the appearance of a particular point in whole higher order cumulants under consideration.