The characterizing variable for critical point in momentum space

TL;DR

This paper proposes that the higher order scaled moments of transverse momentum can signal the critical point in momentum space, demonstrated through a 2-D percolation model showing a sudden change at the critical point.

Contribution

It introduces the use of higher order scaled moments of transverse momentum as a novel observable for detecting the critical point in momentum space.

Findings

Third order scaled moment shows a sudden change at the critical point

The 2-D percolation model confirms the proposed signal

Signal is free from statistical fluctuation contamination

Abstract

The possible experimentally observable signal in momentum space for the critical point, which is free from the contamination of statistical fluctuations, is discussed. It is shown that the higher order scaled moment of transverse momentum can serve as an appropriate signal for this point, provided the transverse momentum distribution has a sudden change when energy increases passing through the critical point. A 2-D percolation model with a linear temperature gradient is constructed to check this suggestion. A sudden change of third order scaled moment of transverse momentum is successfully observed.