Studies of the Equation of State of Asymmetric Nuclear Matter

不对称核物质状态方程的研究

• 批准号: ST/G008833/1
• 负责人: Marielle Chartier
• 金额: $ 4.34万
• 依托单位: University of Liverpool
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2009
• 资助国家: 英国
• 起止时间: 2009 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=ST%2FG008833%2F1
• 关键词: Studies; Equation; State; Asymmetric; Nuclear

This grant proposal is to study the equation of state (EOS) of asymmetric nuclear matter. The EOS is a fundamental property of nuclear matter and describes the relationships between the energy, pressure, temperature, density and isospin asymmetry for a nuclear system. It can be divided into a symmetric matter contribution that is independent of the isospin asymmetry and an isospin term (also known as the symmetry energy) that is proportional to the square of the asymmetry. The EOS of asymmetric nuclear matter is also a quantity of crucial significance in understanding the physics of isolated and binary neutron stars, type II supernovae and neutron star mergers. Strong synergies exist between the research programme of this grant proposal and several high priority STFC programmes in astrophysics which address the physics of neutron stars and gravitational waves, including Advanced LIGO/GEO600, LISA and SKA. Measurements of isoscalar collective vibrations, collective flow and kaon production in energetic nucleus-nucleus collisions have constrained the equation of state for symmetric matter for densities ranging from saturation density to five times saturation density. However, the EOS of asymmetric matter has comparatively few experimental constraints. The international ASYEOS collaboration (Europe, the USA and Japan), of which we are leading members, has recently been formed to study the EOS of asymmetric nuclear matter. In the period of this grant proposal, the collaboration intends to exploit the stable and rare isotope beams already available from existing facilities such as GSI, GANIL, MSU and RIBF-RIKEN to study the behaviour of the symmetry energy from sub-saturation densities (0.5-1.0 times normal nuclear matter density) to supra-saturation densities (2.0 times normal nuclear matter density and above). This will pave the way for studies in the future at new facilities such as FAIR, FRIB and EURISOL. The UK physicists will lead the components of the programme at GSI and GANIL. These components are: (a) neutron/proton flow measurements in Sn+Sn reactions at 200-800 AMeV at GSI, and (b) isospin diffusion measurements in Ca+Ca reactions at 35 AMeV at GANIL.

本研究计划主要研究非对称核物质的物态方程。物态方程是核物质的基本性质，描述了核系统的能量、压力、温度、密度和同位旋不对称性之间的关系。它可以分为一个对称的物质贡献，这是独立的同位旋不对称性和一个同位旋项（也称为对称能），这是成比例的平方的不对称性。非对称核物质状态方程对于理解孤立中子星、双星、II型超新星和中子星星合并等物理现象也具有重要意义。强大的协同作用之间存在的研究计划的拨款建议和几个高优先级的STFC方案在天体物理学，解决中子星和引力波的物理，包括先进的LIGO/GEO 600，丽莎和SKA。在高能核-核碰撞中，对等密度集体振动、集体流和K介子产生的测量已经限制了密度从饱和密度到五倍饱和密度的对称物质的状态方程。然而，非对称物质的物态方程具有相对较少的实验约束。国际ASYEOS合作（欧洲、美国和日本），我们是其中的主要成员，最近成立了研究非对称核物质的EOS。在此期间，合作计划利用GSI，GANIL，MSU和RIBF-RIKEN等现有设施已经提供的稳定和稀有同位素束，研究对称能从亚饱和密度（0.5-1.0倍正常核物质密度）到超饱和密度（2.0倍正常核物质密度及以上）的行为。这将为今后在FAIR、FRIB和EURISOL等新设施进行研究铺平道路。英国物理学家将在GSI和GANIL领导该计划的组成部分。这些组成部分是：（a）在GSI在200-800 AMeV下Sn+Sn反应中的中子/质子流测量，和（B）在GANIL在35 AMeV下Ca+Ca反应中的同位旋扩散测量。

项目成果

Event-by-event mean $$\varvec{p}_{\mathbf {T}}$$ p T fluctuations in pp and Pb-Pb collisions at the LHC

LHC 中 pp 和 Pb-Pb 碰撞的逐个事件平均 $$varvec{p}_{mathbf {T}}$$ p T 波动

• DOI: 10.1140/epjc/s10052-014-3077-y
• 发表时间: 2014
• 期刊: The European Physical Journal C
• 作者: Abelev B