Instituto Nazionale di Fisica Nucleare, Sez. di Catania, Via S Sofia 64 95123 Catania, Italy.
Rep Prog Phys. 2012 Feb;75(2):026301. doi: 10.1088/0034-4885/75/2/026301. Epub 2012 Jan 9.
We review our knowledge on the properties of the nuclear medium that have been studied, over many years, on the basis of many-body theory, laboratory experiments and astrophysical observations. Throughout the presentation particular emphasis is placed on the possible relationship and links between the nuclear medium and the structure of nuclei, including the limitations of such an approach. First we consider the realm of phenomenological laboratory data and astrophysical observations and the hints they can give on the characteristics that the nuclear medium should possess. The analysis is based on phenomenological models, that however have a strong basis on physical intuition and an impressive success. More microscopic models are also considered, and it is shown that they are able to give invaluable information on the nuclear medium, in particular on its equation of state. The interplay between laboratory experiments and astrophysical observations is particularly stressed, and it is shown how their complementarity enormously enriches our insights into the structure of the nuclear medium. We then introduce the nucleon-nucleon interaction and the microscopic many-body theory of nuclear matter, with a critical discussion about the different approaches and their results. The Landau-Fermi liquid theory is introduced and briefly discussed, and it is shown how fruitful it can be in discussing the macroscopic and low-energy properties of the nuclear medium. As an illustrative example, we discuss neutron matter at very low density, and it is shown how it can be treated within the many-body theory. The general bulk properties of the nuclear medium are reviewed to indicate at which stage of our knowledge we stand, taking into account the most recent developments both in theory and experiments. A section is dedicated to the pairing problem. The connection with nuclear structure is then discussed, on the basis of the energy density functional method. The possibility of linking the physics of exotic nuclei and the astrophysics of neutron stars is particularly stressed. Finally, we discuss the thermal properties of the nuclear medium, in particular the liquid-gas phase transition and its connection with the phenomenology on heavy ion reactions and the cooling evolution of neutron stars. The presentation has been taken for non-specialists and possibly for non-nuclear physicists.
我们回顾了多年来基于多体理论、实验室实验和天体物理观测研究核介质性质的知识。在整个介绍过程中，特别强调了核介质与核结构之间可能存在的关系和联系，包括这种方法的局限性。首先，我们考虑了唯象实验室数据和天体物理观测的范围，以及它们可以提供核介质应具有的特性的提示。分析基于唯象模型，但这些模型有很强的物理直觉和令人印象深刻的成功基础。我们还考虑了更微观的模型，并表明它们能够为核介质，特别是其状态方程，提供非常有价值的信息。特别强调了实验室实验和天体物理观测之间的相互作用，并展示了它们的互补性如何极大地丰富了我们对核介质结构的认识。然后，我们引入了核子-核子相互作用和核物质的微观多体理论，并对不同的方法及其结果进行了批判性讨论。介绍了 Landau-Fermi 液体理论，并对其进行了简要讨论，展示了它在讨论核介质的宏观和低能性质方面是多么富有成效。作为一个说明性的例子，我们讨论了极低密度下的中子物质，并展示了如何在多体理论中对其进行处理。我们回顾了核介质的一般体性质，以表明在考虑到理论和实验的最新发展的情况下，我们在知识的哪个阶段。有一节专门讨论了配对问题。然后，根据能量密度泛函方法，讨论了与核结构的联系。特别强调了将奇异核物理与中子星天体物理联系起来的可能性。最后，我们讨论了核介质的热性质，特别是液体-气体相变及其与重离子反应的唯象学和中子星冷却演化的关系。本演讲面向非专业人士，也可能面向非核物理学家。
