物理系colloquium：Nuclear Symmetry Energy – from nucleus to neutron star

報告題目： Nuclear Symmetry Energy – from nucleus to neutron star 報告人： Betty Tsang National Superconducting Cyclotron Laboratory, Michigan State University 報告時間： 2013-9-26 16:00 報告地點：理科樓鄭裕彤大講堂摘要： When a system moves away from equal number of neutron and protons, the energy increases. This “penalty” is termed the symmetry energy, similar to the term in the liquid drop model mass formula. Effects of the symmetry energy are especially important in systems with very different composition of neutron and proton such as neutron stars and heavy nuclei. Substantial progress has been achieved in recent years in constraining the density dependence of nuclear symmetry energy at and around the saturation density with a wide range of experiments and nuclear masses. Recent discovery of a two solar-mass neutron star suggests that the symmetry energy at high density is large. However, recent extraction of neutron star radius of around 9 km provides the apparently contradictory evidence that the density dependence of symmetry energy is weak above the saturation density. In this talk, I will review these results and discuss new experimental programs in Asia and in the US to probe the symmetry energy using heavy ion reactions. 個人簡介： Betty Tsang is a professor at the National Superconducting Cyclotron Laboratory, an Adjunct Professor at the Department of Physics and Astronomy and a core faculty member of the Center for Advance Study of International Development at Michigan State University. She was born in Hong Kong and received her primary and secondary education there before moving to the U.S. She received her PhD in Nuclear Chemistry at the University of Washington, Seattle. After graduation in 1980, she went to Michigan State University as a postdoctoral fellow and has been working there ever since.
In her research Tsang has investigated the equation of state and liquid gas phase transition of nuclear matter, the production of rare isotopes, and single particle structure of the nucleus via transfer reactions. Since 1980, she has published more than 250 articles in refereed journals. She has 10755 citations in google scholar. Her work has involved collaborations of scientists from China, Brazil, Canada, France, Germany, Italy, Japan, Russia, and Vietnam. She has organized numerous conferences with international participants including an upcoming conference at Xi-Chang in January. She became an American Physical Society Fellow in 2006. In 2000, she received the Heinz Pagels award from the New York Academy of Sciences