From April 6 to 12, 2026, the 2nd PandaX-xT International Open Meeting was successfully held at the Tsung-Dao Lee Institute. This marked the second international open meeting organized by the PandaX Collaboration since 2025. The meeting attracted nearly one hundred researchers from the United States, the United Kingdom, France, Germany, Japan, Russia, the Czech Republic, Slovakia, Australia, mainland China, and Taiwan, China. The conference was jointly chaired by Prof. Yifei Niu from Shanghai Jiao Tong University, Prof. Jianglai Liu from the Tsung-Dao Lee Institute, Prof. Fedor Šimkovic from Comenius University, and Prof. Qing Lin from University of Science and Technology of China.
The PandaX (Particle and Astrophysical Xenon Experiment) project, led by the Tsung-Dao Lee Institute and based at the China Jinping Underground Laboratory, aims to explore dark matter particles and neutrino properties through a series of progressively upgraded xenon detectors. PandaX-xT is envisioned as a next-generation, multi-ten-ton ultra-low-background liquid xenon platform dedicated to searches for dark matter, Majorana neutrinos, low-energy astrophysical neutrinos, and other extremely rare interactions. While the current-stage experiment, PandaX-4T, has been operating since 2021, the collaboration is actively advancing the development of the future PandaX-xT detector system.
The meeting consisted of two parts: a five-day Focused Workshop and a two-day PandaX-xT International Open Meeting. The Focused Workshop, titled “Nuclear and Atomic Physics in Dark Matter and Neutrino Physics,” gathered leading scientists from around the world to discuss theoretical challenges closely related to the PandaX experiment, including detectable signals and urgently needed theoretical calculations. Each day featured four to five one-hour presentations, fostering active discussions and strengthening collaborations between theorists and the PandaX experimental team. The future multi-ten-ton liquid xenon detector is designed to achieve an exceptionally low background level and support frontier research across multiple disciplines.
The two-day PandaX-xT Open Meeting was co-organized by the University of Science and Technology of China and Huangshan University. During the meeting, the PandaX Collaboration presented the implementation plan for the next-generation PandaX-20T experiment, including detailed subsystem designs, recent R&D progress, and future plans. The experiment is expected to begin commissioning next year. The collaboration also formally invited researchers worldwide to join the PandaX-20T program. Experts engaged in extensive discussions on the scientific opportunities and technical challenges associated with the experiment, and many expressed strong interest in participating in the collaboration.
The full-scale PandaX-xT experiment will ultimately employ a 40-ton xenon target, enabling groundbreaking studies in dark matter searches, Majorana neutrino physics, astrophysical neutrino observations, and other ultra-rare particle interactions.
At the opening ceremony, Prof. Jianglai Liu, Deputy Director of the Tsung-Dao Lee Institute and one of the initiators of the meeting, delivered the welcome address. The conference chairs included Prof. Jianglai Liu, Prof. Yifei Niu, Prof. Qing Lin, and Prof. Fedor Šimkovic.
The meeting first hosted a five-day theory and phenomenology workshop, followed by the two-day open meeting. During the open sessions, the PandaX Collaboration outlined the staged implementation strategy for PandaX-xT and introduced the design details and preparation progress of each subsystem. Around thirty international experts shared insights into the scientific opportunities and technical challenges of PandaX-xT throughout the program.
The conference focused on frontier topics in dark matter physics and attracted researchers from internationally renowned institutions, including CNRS, Max Planck Institute for Nuclear Physics, RIKEN, Technical University of Munich, University College London, University of Warwick, and the Czech Technical University in Prague, as well as leading universities and institutes from mainland China, Hong Kong, Macau, and Taiwan, including Shanghai Jiao Tong University, Tsinghua University, Sun Yat-sen University, and National Dong Hwa University. Through invited talks and discussions, participants explored key scientific questions related to dark matter and associated research areas.
Following extensive discussions, participants reached broad consensus on many scientific and technical issues related to the PandaX experiment. Taking this opportunity, the PandaX Collaboration officially extended an open invitation to researchers worldwide to join the collaboration and contribute to the future development of the PandaX program.
The collaboration looks forward to welcoming researchers again at future meetings to continue advancing dark matter research and opening new chapters in the exploration of the universe.
On April 14, several invited experts also visited the China Jinping Underground Laboratory for an on-site tour.
This meeting was strongly supported by the National Key Laboratory of Dark Matter Physics, the National Natural Science Foundation of China, and the Tencent Foundation through the New Cornerstone Investigator Program