The behaviour of constrained caloric curves as ultimate signature of a phase transition for hot nuclei

TL;DR

This study uses simulations of nuclear collisions to analyze caloric curves, revealing a backbending at constrained pressures that supports the existence of a first-order phase transition in hot nuclei.

Contribution

It demonstrates the behavior of constrained caloric curves and provides evidence for a phase transition in hot nuclei through simulation-based analysis.

Findings

Caloric curves are monotonous at constant volume.

Backbending observed at constrained pressures.

Supports first-order phase transition in hot nuclei.

Abstract

Simulations based on experimental data obtained from multifragmenting quasifused nuclei produced in central 129Xe + natSn collisions have been used to deduce event by event freeze-out properties on the thermal excitation energy range 4-12 AMeV. From these properties and temperatures deduced from proton transverse momentum fluctuations constrained caloric curves have been built. At constant average volumes caloric curves exhibit a monotonous behaviour whereas for constrained pressures a backbending is observed. Such results support the existence of a first order phase transition for hot nuclei.