U.S.-Japan Cooperative Research: Investigation of Microscopic Structure of Exotic Compressional-Mode Giant Resonances

该奖项支持圣母大学Umesh Garg教授和日本柯南大学Hidetoshi Akimune教授为期三年的国际合作研究项目。他们将进行奇异压缩模巨共振的微观结构研究。提出的测量旨在通过重合测量来研究压缩模式巨共振——巨单极子共振（GMR）和等标量巨偶极子共振（ISGDR）的微观结构。压缩模共振的重要性在于它们的能量与核的不可压缩性有关。核不可压缩性是核状态方程（EOS）的一个重要组成部分。在核物理学中，对EOS的研究是由原子核特有的方面所驱动的，特别是它可以被认为是一个双流体量子液滴。EOS对于理解中子星的性质至关重要，中子星是自然界中存在的“最大的原子核”。事实上，核物质的可压缩性强烈地影响着中子星的结构、它们抗引力坍缩的稳定性、它们在超新星爆炸期间的产生以及它们冷却的方式。该项目汇集了几个具有互补专业知识和研究能力的实验室的努力。美国研究人员在巨型共振研究方面开发的专业知识，以及日本大阪核物理研究中心（RCNP）一流的实验设施，为合作伙伴提供了巨大的互惠效益。预计这项工作将有助于天体物理学领域，因为从这些研究中获得的信息可能会影响我们对“中子星”的理解。该项目通过一批博士后、研究生和本科生的参与来促进国际人力资源的发展。通过思想和技术的交流，该项目将扩大我们的基础知识基础，促进国际了解与合作。研究结果将在科学会议和科学期刊上传播。

0342942GargThis award supports a three-year international collaborative research project between Professor Umesh Garg at the University of Notre Dame and Professor Hidetoshi Akimune at Konan University in Japan. They will undertake a study on investigation of microscopic structure of exotic compressional-mode giant resonances. The proposed measurements aim at investigating the microscopic structure of the compressional-mode giant resonances - the Giant Monopole Resonance (GMR) and the Isoscalar Giant Dipole Resonance (ISGDR) - via coincidence measurements. The importance of the compresssional-mode resonances lies in that their energies are related to the nuclear incompressibility. The nuclear incompressibility is a critical component of the nuclear equation of state (EOS). In nuclear physics, the search for EOS is motivated by aspects unique to the nucleus, especially that it can be considered as a two-fluid quantal droplet. The EOS is crucial to understanding the properties of neutron stars, the "largest nuclei" that exist in nature. Indeed, the compressibility of nuclear matter strongly influences the structure of the neutron stars, their stability against gravitational collapse, their production during supernova explosions, and their manner of cooling. The project brings together the efforts of several laboratories that have complementary expertise and research capabilities. The expertise developed by the U.S. researchers in giant resonance studies, and the superb experimental facilities at RCNP (the Research Center for Nuclear Physics) in Osaka, Japan provide a synergy with tremendous mutual benefits for the collaborative partners. It is expected that this work will contribute to the field of astrophysics, as the information attained from these studies may impact our understanding of "neutron stars." The project advances international human resources through the participation of a number of postdocs, graduate students and undergraduate students. Through the exchange of ideas and technology, this project will broaden our base of basic knowledge and promote international understanding and cooperation. Results of the research will be disseminated at scientific meetings and in scientific journals.