Window on the Universe: Equation of State of Asymmetric Nuclear Matter

宇宙之窗：不对称核物质的状态方程

• 批准号: 2209145
• 负责人: William Lynch
• 金额: $ 135万
• 依托单位: Michigan State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2209145&HistoricalAwards=false
• 关键词: Window; Universe; Equation; State; Asymmetric

Windows on the Universe: Equation of state of Asymmetric Nuclear Matter The spectacular GW170817 gravitational wave (GW) observations of a Neutron Star (NS) merger by the LIGO-Virgo collaboration were accompanied by the detection of gamma-rays, optical and radio signals. These coordinated observations were the fruit of cutting-edge scientific investments by the U.S. These investments usher in a new era of synchronous multi-messenger astrophysics, and provide definitive links between NS mergers, kilonovae and gamma-ray bursts, and between NS mergers and the nucleosynthesis of heavy elements. The proposed research plan broadens these multi-messenger studies to include relevant messages from experimental constraints on the forces within neutron-rich matter that support the NS. It addresses questions of the 2015 Long Range Plan for Nuclear Science concerning the nature of neutron stars and dilute and dense nuclear matter by focusing on properties of nuclear forces that depend on neutron-to-proton imbalance. Michigan State University and FRIB sponsor research for under-represented physics students, which will help to attract a diverse group of talented undergraduate students, graduate students and postdocs to this project. These young scientists will learn about detector design and construction, complex multi-parameter data analyses, detector simulations and theoretical modeling, machine learning and Bayesian inference analyses. This training prepares them for leadership roles in the future work force both in nuclear science but also in other key areas important for technological advancement and national security. Both the GW170817 gravitational wave observations and recent messages on Neutron Star (NS) radii from the Neutron star Interior Composition Explorer (NICER) constrain the relationship between the total pressure and the matter density within NS. Neither astronomical observation isolates the symmetry energy, however. The symmetry energy is a term in the Equation of State (EoS) that arises from the imbalance in the numbers of neutrons and protons in the matter. It plays a dominant role regarding the stability of a NS. The symmetry energy governs the relative numbers of neutrons and protons, and the density and pressure where the liquid NS core ends and solid crust begins. The symmetry energy also governs whether anti matter or strange matter exist within neutron stars. The group will study the symmetry energy via experimental studies and isolate its role by varying the relative numbers of neutrons and protons and also the density of the system from ¼ to twice normal nuclear matter density. They will perform experiments at RIKEN in Japan, using cutting edge instrumentation and a collaborative effort between theory and experiment to connect the findings to emerging results from multi-messenger astronomy. By combining these new measurements of the symmetry energy with existing experimental constraints on the EoS of symmetric matter which contains equal numbers of neutrons and protons, they will also obtain the EoS of pure neutron matter which is also of fundamental interest. While the focus of the student training is on scientific and technological advancement, they will also engage young scientists in outreach activities to make this science more accessible to non-scientists. They have created websites using virtual reality apps to illustrate nuclear collisions, the detection of cosmic rays and the working principles of our time projection chamber. By such efforts, they will endeavor to make the science more appealing and exciting to the general public.This project advances the objectives of "Windows on the Universe: the Era of Multi-Messenger Astrophysics", one of the 10 Big Ideas for Future NSF Investments.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

宇宙之窗：不对称核物质的状态方程 LIGO-Virgo 合作对中子星 (NS) 合并进行了壮观的 GW170817 引力波 (GW) 观测，同时还检测到了伽马射线、光学和无线电信号。这些协调观测是美国尖端科学投资的成果。这些投资开创了同步多信使天体物理学的新时代，并在 NS 之间提供了明确的联系。合并、千新星和伽马射线暴，以及核子合并和重元素核合成之间的研究计划扩大了这些多信使研究，以包括来自支持核子的富中子物质内力的实验限制的相关信息。它通过关注依赖于核力的性质，解决了 2015 年核科学长期计划中有关中子星以及稀核物质和稠密核物质性质的问题。密歇根州立大学和 FRIB 资助了针对代表性不足的物理学学生的研究，这将有助于吸引各种有才华的本科生、研究生和博士后参与该项目，这些年轻科学家将学习探测器设计。该培训为他们在核科学以及对技术进步和其他重要领域的未来工作中发挥领导作用做好了准备。国家安全。 GW170817 引力波观测和中子星内部成分探测器 (NICER) 的最新消息都限制了 NS 内总压力和物质密度之间的关系，然而，这两种天文观测都没有孤立对称能量。对称能是状态方程（EoS）中的一项，由物质中中子和质子数量的不平衡产生，它起着主导作用。关于中子星的稳定性，对称能量决定着中子和质子的相对数量，以及液体中子星核心结束处和固体地壳开始处的密度和压力，对称能量还决定着中子星内是否存在反物质或奇异物质。该小组将通过实验研究对称能，并通过改变中子和质子的相对数量以及系统密度（从 1/4 到正常核物质密度）来分离其作用。他们将在 RIKEN 进行实验。在日本，利用尖端仪器以及理论和实验之间的合作，将对称能量的这些新测量结果与包含等量对称物质的 EoS 的现有实验限制相结合，将这些发现与多信使天文学的新结果联系起来。除了中子和质子的数量外，他们还将获得纯中子物质的EoS，这也是人们的根本兴趣。虽然学生培训的重点是科学技术进步，但他们还将让年轻科学家参与推广活动，以推动这门科学的发展。他们使用虚拟现实应用程序创建了网站，以说明核碰撞、宇宙射线的探测和我们的时间投影室的工作原理，通过这些努力，他们将努力使科学更具吸引力和令人兴奋。该项目推进了“宇宙之窗：多信使天体物理学时代”的目标，这是未来 NSF 投资的 10 大创意之一。该奖项反映了 NSF 的法定使命，并被视为值得通过使用基金会的智力优点和更广泛的影响审查标准进行评估来支持。

项目成果

Isoscaling in central Sn+Sn collisions at 270 MeV/u

• DOI: 10.1140/epja/s10050-022-00851-2
• 发表时间: 2022-10
• 期刊: The European Physical Journal A
• 作者: J. Lee;M. Tsang;C. Tsang;R. Wang;J. Barney;J. Estee;T. Isobe;M. Kaneko;M. Kurata-Nishimura;W. G. Lynch;T. Murakami;A. Ono;S. Souza;D. Ahn;L. Atar;T. Aumann;H. Baba;K. Boretzky;J. Brzychczyk;G. Cerizza;N. Chiga;N. Fukuda;I. Gašparić;B. Hong;A. Horvat;K. Ieki;N. Ikeno;N. Inabe;G. Jhang;Y. Kim;T. Kobayashi;Y. Kondo;P. Lasko;H. Lee;Y. Leifels;J. Lukasik;J. Manfredi;A. McIntosh;P. Morfouace;T. Nakamura;N. Nakatsuka;S. Nishimura;H. Otsu;P. Pawlowski;K. Pelczar;D. Rossi;H. Sakurai;C. Santamaria;H. Sato;H. Scheit;R. Shane;Y. Shimizu;H. Simon;A. Snoch;A. Sochocka;T. Sumikama;H. Suzuki;D. Suzuki;H. Takeda;S. Tangwancharoen;Y. Togano;Z. Xiao;S. Yennello;Y. Collaboration;D. Physics;Korea University;Seoul.;R. Korea.;Facility for Rare Isotope Beams;M. University;E. Lansing.;Michigan.;Usa;Astronomy;Riken Nishina Center;Wako;Saitama;Japan.;Kyoto University;T. University;Sendai;I. D. F'isica;U. F. R. D. Janeiro;Centro Interuniversitario de Historia das Ciencias e da Tecnologia-Centro-Interuniversitario-de-Historia-das-Ciencias-72426587;A. Bloco;R. Janeiro;Brazil;Departamento de Engenharia Nuclear;Universidade Federal de Minas Gerais Ufmg;Av. Antônio Carlos;M. Gerais;I. F. Kernphysik;Technische Universitat Darmstadt;Darmstadt;Germany;G. H. F. Schwerionenforschung;F. O. Physics;A. Science;J. University;Krak'ow;Poland;D. Physics;Rudjer Boskovic Institute;Zagreb;Croatia.;R. University;Tokyo;Department of Life;E. Sciences;Tottori University;Rare Isotope Science Project;Institute for Computational Science;Daejeon;Tokyo Institute of Technology;Institute of Nuclear Physics Pan;C. Institute;Texas A M University;College Station;Texas;Nikhef National Institute for Subatomic Physics;Amsterdam;Netherlands.;Tsinghua University;Beijing;P. China;D. Chemistry

Determination of energy-dependent neutron backgrounds using shadow bars

• DOI: 10.1016/j.nima.2023.168341
• 发表时间: 2022-12
• 期刊: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
• 作者: S. Paneru;K. Brown;F. Teh;K. Zhu;M. Tsang;D. DellAquila;Z. Chajecki;W. G. Lynch;S. Sweany;C. Tsang;A. Anthony;J. Barney;J. Estee;I. Gašparić;G. Jhang;O. Khanal;J. Manfredi;C. Niu;R.S. Wang;J. Zamora

Constraints from isoscaling on the source size in energetic heavy ion collisions

高能重离子碰撞中等尺度对源尺寸的约束

• DOI: 10.1103/physrevc.106.034606
• 发表时间: 2022
• 期刊: Physical Review C
• 影响因子: 3.1
• 作者: Souza, S. R.;Donangelo, R.;Lynch, W. G.;Tsang, M. B.
• 通讯作者: Tsang, M. B.