Is bimodality a sufficient condition for a first order phase transition existence?

Abstract

Here we present two explicit counterexamples to the widely spread beliefs about an exclusive role of bimodality as the first order phase transition signal. On the basis of an exactly solvable statistical model generalizing the statistical multifragmentation model we demonstrate that the bimodal distributions can naturally appear both in infinite and in finite systems without a phase transition. In the first counterexample a bimodal distribution appears in an infinite system at the supercritical temperatures due to the negative values of the surface tension coefficient. In the second counterexample we explicitly demonstrate that a bimodal fragment distribution appears in a finite volume analog of a gaseous phase. In contrast to the statistical multifragmentation model, the developed statistical model corresponds to the compressible nuclear liquid with the tricritical endpoint located at one third of the normal nuclear density. The suggested parameterization of the liquid phase equation of state is consistent with the L. van Hove axioms of statistical mechanics and it does not lead to an appearance of the non-monotonic isotherms in the macroscopic mixed phase region which are typical for the classical models of the Van der Waals type. Peculiarly, such a way to account for the nuclear liquid compressibility automatically leads to an appearance of an additional state that in many respects resembles the physical antinuclear matter.

22 pages, 9 figures

References in corpus (8)

• Bimodal behavior of the heaviest fragment distribution in projectile fragmentation
• Bimodality: a possible experimental signature of the liquid-gas phase transition of nuclear matter
• Model-independent tracking of criticality signals in nuclear multifragmentation data
• The role of superfluidity in nuclear incompressibilities
• Quark-Gluon Bags with Surface Tension
• Looking for bimodal distributions in multi-fragmentation reactions
• Signals of bimodality in the fragmentation of Au quasi-projectiles
• Bimodalities : a survey of experimental data and models

Cited by in corpus (4)

• The statistical multifragmentation model for liquid-gas phase transition with a compressible nuclear liquid
• The Flow Constraint Influence on the Properties of Nuclear Matter Critical Endpoint
• Effects of Induced Surface Tension in Nuclear and Hadron Matter
• Finite size effects on the phase diagram of the thermodynamical cluster model