On November 4th, 2022, the Gezhi Forum (13th lecture) of the School of Physics, Peking University was held in Siyuan Hall. Yang Xiaofei, the Research Professor of Department of Technical Physics and State Key Laboratory of Nuclear Physics and Technology, gave a report entitled “New Opportunities from Atoms and Molecules Containing Radioactive Nucleus”. Professor Mao Yajun chaired the forum.

Yang first introduced an interdisciplinary method for studying the basic properties and structure of atomic nuclei. This method, named as nuclear laser spectroscopy, can measure the basic properties of nucleus in a nuclear-model-independent manner by probing the subtle changes in the energy levels of electrons resulting from the interaction between the atomic nucleus and surrounding electrons. In the 100 years history of nuclear physics study, this experimental method has played an important role. In the past 30 years, with the continouse development of radioactive ion beam facilties, more and more unstable nuclei have became experimentally accessible, revealing many unexpected structural phenomena of atomic nuclei with unusual proton-to-neutron ratios. Laser spectroscopy techniques, with their continuous technological development and innovation towards higher resolution and higher sensitivity, have made significant contributions to our understanding of these unstable nuclei in different mass regions, offering prominent tests of state-of-the-art theory models. This has been demonstrated by Yang’s recent work on the study of the exotic structure of atomic nuclei. In particular, she presented the recent work of her group on the development of the first laser spectroscopy set up for the study of unstable nuclei at the radioactive ion beam faciltity facilities of China, such as the Beijing Radioactive Beam Facility BRIF. Then, she introduced an innovative work of CRIS collaboration on the study of molecules containing short-lived nuclei, which offers additional opportunities for several fields of research, e.g. fundamental symmetry studies and astrophysics.

After the presentation, Yang discussed with the audiences about the advantages，experimental challeneges and future prospects of laser spectroscopy method for the study of atoms and molecules containing radioactive nucleus.

This on-site forum was also broadcast live online. An audience of over 750 thousand joined in via Peking University’s official account on Wechat Channel, Bilibili, TikTok, Kuaishou and KouShare.