First-order Phase Transition and Resulted Expansion in Momentum Space

TL;DR

This paper demonstrates that during a first-order phase transition, the system's momentum space volume expands, supported by simulations and novel observables that can probe such transitions in heavy-ion collisions.

Contribution

It introduces a new perspective on momentum space expansion during phase transitions and proposes observables to detect this phenomenon in experimental settings.

Findings

Momentum space volume expands during first-order phase transition.

Simulation results support the entropy growth principle.

New observables proposed for experimental detection.

Abstract

We point out, according to the principle of entropy growth, that the volume occupied by the system in the momentum space should expand during the first-order phase transition. Such an expansion is visualized by the simulation using the transport model based on a NJL-typed Lagrangian, and quantified by several observables, some of which, proposed for the first time in this article, could be the probes of the first-order phase transition either between the quark gluon plasma and the hadronic phase taking place in the heavy-ion collisions or of the other expanding systems.