283 research outputs found
Effects of Induced Surface Tension in Nuclear and Hadron Matter
Short range particle repulsion is rather important property of the hadronic
and nuclear matter equations of state. We present a novel equation of state
which is based on the virial expansion for the multicomponent mixtures with
hard-core repulsion. In addition to the hard-core repulsion taken into account
by the proper volumes of particles, this equation of state explicitly contains
the surface tension which is induced by another part of the hard-core repulsion
between particles. At high densities the induced surface tension vanishes and
the excluded volume treatment of hard-core repulsion is switched to its proper
volume treatment. Possible applications of this equation of state to a
description of hadronic multiplicities measured in A+A collisions, to an
investigation of the nuclear matter phase diagram properties and to the neutron
star interior modeling are discussed.Comment: Proceedings of the XII Quark Confinement and Hadron Spectrum
Conference (CONF12), 5 pages, 8 figure
Bimodality Phenomenon in Finite and Infinite Systems Within an Exactly Solvable Statistical Model
We present a few explicit counterexamples to the widely spread belief about
an exclusive role of the bimodal nuclear fragment size distributions as the
first order phase transition signal. In thermodynamic limit the bimodality may
appear at the supercritical temperatures due to the negative values of the
surface tension coefficient. Such a result is found within a novel exactly
solvable formulation of the simplified statistical multifragmentation model
based on the virial expansion for a system of the nuclear fragments of all
sizes. The developed statistical model corresponds to the compressible nuclear
liquid with the tricritical endpoint located at one third of the normal nuclear
density. Its exact solution for finite volumes demonstrates the bimodal
fragment size distribution right inside the finite volume analog of a gaseous
phase. These counterexamples clearly demonstrate the pitfalls of Hill approach
to phase transitions in finite systems.Comment: Talk given at the Helmholtz International Summer School "Physics of
Heavy Quarks and Hadrons", held in Dubna, Russia, July 15-28, 201
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