Chiral thermodynamics of nuclear matter

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• 作者：Salvatore Fiorilla ; ^{salvatore.fiorilla@ph.tum.de} ; Norbert Kaiser ; Wolfram Weise
• 关键词：Chiral perturbation theory ; Nuclear matter ; Equation of state ; Thermodynamics ; Phase diagram ; Liquid&ndash ; gas phase transition
• 刊名：Nuclear Physics A
• 出版年：2012
• 出版时间：15 April, 2012
• 年：2012
• 卷：880
• 期：Complete
• 页码：65-87
• 全文大小：1148 K

文摘

The free energy and the equation of state of isospin-asymmetric nuclear matter are calculated at finite temperature up to three loop order in the framework of in-medium chiral perturbation theory, systematically incorporating one- and two-pion exchange dynamics to this order. Effects from the 2¦Ð-exchange with explicit ¦¤-isobar excitation are included, as well as three-body forces. We construct the phase diagram of nuclear matter for different proton fractions and investigate the dependence of nuclear matter properties on the isospin-asymmetry. A detailed study of the liquid-gas phase transition is performed. For isospin-symmetric nuclear matter we find a critical temperature of 15.1 MeV; as the isospin-asymmetry is increased, the liquid-gas coexistence region decreases until it disappears at , while nuclear matter becomes unbound at . The quadratic expansion of the free energy in the asymmetry parameter ¦Ä is a good approximation at low temperature even for large ¦Ä. An estimate of chiral four-body correlations in nuclear and neutron matter is also performed and the corrections from such four-body interactions are found to be small.