Haiyan Gao, Henry Newson Professor and Chair of Dept. of Physics, Duke University, was invited to visit WIPM by the division of theoretical and interdisciplinary research. During her visit, she gave a report on the frontier of the experimental nuclear physics and shared her research experience with us. This academic activity was at the 50thlecture of the academic series in the division of theoretical and interdisciplinary research, so the lecture hall was crowded early.
Prof. Gao first shared her research experience in the talk. After getting her bachelor degree from Tsinghua University in 1988, Prof. Gao went to California Institute of Technology in the USA to study for a doctoral degree, and received herPhD in 1994, and then went to the University of Illinois forthe postdoctoral research and Argonne National Laboratory as an assistant physicist. From 1997 to 2002,Prof. Gao was an assistant professor of the department of physics, Massachusetts Institute of Technology, and then was appointed as associate professor (tenured) in department of physics, Duke University, she was appointed full professor in July 2008. Recalling her experience, Prof. Gao told the graduate students in audience how to choose a research field and the tutor.She believed that interest is the best teacher, so to do what you love was the most important thing. For graduate study and research, she hold the opinion that being into the research field as soon as possible and cultivating the ability to do research independently, was crucial to the development of the entire research process. "Busy, challenging, exciting, overwhelming and rewarding" was her life at the Massachusetts Institute of Technology , she used this to encourage graduates to work with passion.
In the second part of the talk, Prof. Gao introduced her research work on nuclear structure. The standard model is very successful in particle physics, although it is not a success as to the gravitational interaction unified, the strong interaction, weak interaction and electromagnetic interactions are within the prediction of this theory. Quantum chromodynamics (QCD) is a component of the standard model of particle physics, which is to describe the strong interaction. Protons are "hydrogen" in quantum chromodynamics, people’s research on its quality, charged radius, spin has never been interrupted. CODATA recommended value of proton charge radius is Rp=0.8768(69) fm, mainly based on electron and proton scattering experiment. In 2010, R. Pohl’ team use pulsed laser spectroscopy to measure a muonic Lamb shift in the Max Planck Institute, they find Rp = 0.84184 (67) fm, which differs by 5.0 standard deviations from CODATA’s value. Another group in Max Planck Institute remeasured the 2S-2P transition by A. Antognini in 2013, they extracted Rp = 0.84087 (39) fm, thus reinforcing the proton radius puzzle. This promote physical experimenters to rethink the system error of electron scattering experiments . Unlike electron scattering experiments using magnetic spectrometer to do big angle measurement, Prof. Gao will use the electromagnetic calorimeter to do small-angle electron - proton scattering experiments, not only the amount of energy of charged hadrons can be measured, but also the neutral hadron can, at the same time the range of energy can cover several orders of magnitude, these can not be achieved by magnetic spectrometer. Prof. Gao’s group want to use a different experimental method to minimize systematic errors in electron scattering experiments.