Going beyond the second virial coefficient in the hadron resonance gas modelShow others and affiliations
2018 (English)In: Nuclear Physics A, ISSN 0375-9474, E-ISSN 1873-1554, Vol. 970, p. 133-155Article in journal (Refereed) Published
Abstract [en]
We develop a novel formulation of the hadron resonance gas model which, besides a hard-core repulsion, explicitly accounts for the surface tension induced by the interaction between the particles. Such an equation of state allows us to go beyond the Van der Waals approximation for any number of different hard-core radii. A comparison with the Carnahan Starling equation of state shows that the new model is valid for packing fractions 0.2-0.22, while the usual Van der Waals model is inapplicable at packing fractions above 0.1-0.11. Moreover, it is shown that the equation of state with induced surface tension is softer than the one of hard spheres and remains causal at higher particle densities. The great advantage of our model is that there are only two equations to be solved and neither their number nor their form depend on the values of the hard-core radii used for different hadronic resonances. Such an advantage leads to a significant mathematical simplification compared to other versions of truly multi-component hadron resonance gas models. Using this equation of state we obtain a high-quality fit of the ALICE hadron multiplicities measured at the center-of-mass energy 2.76 TeV per nucleon and we find that the dependence of chi(2)/ndf on the temperature has a single global minimum in the traditional hadron resonance gas model with the multi-component hard-core repulsion. Also we find two local minima of chi(2)/ndf in the model in which the proper volume of each hadron is proportional to its mass. However, it is shown that in the latter model a second local minimum located at higher temperatures always appears far above the limit of its applicability. (C) 2017 Elsevier B.V. All rights reserved.
Place, publisher, year, edition, pages
ELSEVIER SCIENCE BV , 2018. Vol. 970, p. 133-155
Keywords [en]
Hadron resonance gas model; Hard-core repulsion; Induced surface tension
National Category
Other Physics Topics
Identifiers
URN: urn:nbn:se:liu:diva-147158DOI: 10.1016/j.nuclphysa.2017.11.008ISI: 000427447200010OAI: oai:DiVA.org:liu-147158DiVA, id: diva2:1199481
Note
Funding Agencies|program "Nuclear matter under extreme conditions"; Fundacao para a Ciencia e a Tecnologia (FCT), Portugal [UID/FIS/00099/2013]; ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum fur Schwerionenforschung, Darmstadt, Germany; Ministry of Science and Education of the Russian Federation [3.3380.2017/4.6]; National Research Nuclear University "MEPhI" in the framework of the Russian Academic Excellence Project [02.a03.21.0005]
2018-04-202018-04-202020-03-26