Identifying and elucidating the fundamental laws of nature drives particle and nuclear physics research. While enormous strides in this quest have been made over the centuries—the establishments of the Standard Model of Electroweak and Strong Interactions and the Standard Big Bang model of Cosmology, deep mysteries remain to be unraveled, such as:
- What is the fundamental structure of matter and their interactions, and do space-time and the laws of matter emerge from more fundamental structures?
- How do elementary particles and their interactions drive the evolution of the universe and astrophysical objects from the beginning of the Big Bang to the end?
- What is the cosmological “dark matter”?
- Why does the universe contain more matter than antimatter?
- Are there new interactions or new “exotic” states of matter beyond the standard particle and cosmological models?
The Division of Particle and Nuclear Physics carries out cutting-edge research connecting particle and nuclear physics with the cosmos. Our general vision is to develop China-based, high-visibility, high-impact research with strong international collaborations, and to become an innovation center that integrates theory and experiment in this area.
Currently, this division has three research groups working on various projects to unravel the laws of nature. The division works closely with the Institute of Nuclear and Particle Physics (INPAC) at SJTU.
Underground Experimental Group
The underground experiments rely on an exquisitely low background environment to study some of the most profound questions in nature. In the past thirteen years at the China Jinping Underground Laboratory (CJPL), we have developed a staged experimental program using liquid xenon detectors, PandaX, now one of the world’s leading experiments in dark matter direct detection. We also participate in large-scale neutrino experiments to understand the fundamental properties of neutrinos and to use them as messengers for new phenomena. Current research projects we lead or participate in include dark matter and neutrinoless double beta decay experiments, namely PandaX; reactor and cosmic neutrino experiments, namely Jiangmen Underground Neutrino Observatory (JUNO), IceCube, and the TRopIcal DEep-sea Neutrino Telescope (TRIDENT). In particular, TRIDENT is a new TDLI-led neutrino telescope initiative in the West Pacific Ocean.
Accelerator-based Experimental Group
Using accelerators as tools, this group explores the high energy and the precision frontier of particle physics, to study fundamental physics in the early universe, and to explore new physics beyond the Standard Model. Since 2012, we have established research groups for the A Toroidal LHC Apparatus (ATLAS) experiment at CERN, and for the Muon g-2 experiment at the Fermilab and muon EDM initiative at PSI. We also play an important role in the development of China’s future Higgs/W/Z bosons factories Circular Electron Positron Collider (CEPC). For the future, we have initiated the R&D of the DarkSHINE program (search for dark matter and mediator dark photon) and a muon source R&D based on the Shanghai Hard X-ray Free Electron Laser facility (SHINE) in Shanghai.
Theory Group
Since its establishment, the theory group has been working closely with experimental groups and developing various independent programs in particle physics, nuclear physics, and cosmology. We have an excellent program on phenomenology on high-energy colliders, neutrino properties, flavor physics, dark matter, and dark energy. In connection to the cosmos, we host a world-leading program in the quantum field theory of the early universe, focusing on the cosmic phase transition, baryogenesis, gravitational waves, and inflation. We also pursue a deeper understanding of the structure of matter using lattice gauge theory to study the low-energy dynamics of quantum chromodynamics.