内容摘要：Neutrinos are the only known elementary particles that are Majorana fermion candidates, implying that they would be their own antiparticles. The most sensitive and perhaps only practical probe of the Majorana nature of neutrinos is an extremely rare nuclear decay process, the double beta decay without the emission of neutrinos. After a brief introduction to neutrinos and the physics of neutrinoless double beta decay, I will present the main experimental techniques to search for this extraordinary rare decay. The focus will be on the LEGEND projects. I will show first results from the LEGEND-200 experiment at LNGS, which deploys about 200 kg of HPGe detectors enriched in 76-Ge in ultra-pure liquid argon. I will also discuss the prospects to probe the inverted neutrino mass ordering scenario with the next phase in the project, LEGEND-1000, which will be constructed in Hall C of LNGS.

报告人简介：Laura Baudis is a professor in the Physics Department of the University of Zurich. She currently serves as the head of department. She has a long interest in dark matter and neutrino physics and has worked on dark matter detectors since her days as a PhD student at the University of Heidelberg. Her research focusses on developing detectors for the direct detection of dark matter particles and for elucidating the nature of neutrinos. Laura Baudis is a fellow of the American Physical Society, a member of the Academy of Sciences and Literature, Mainz and in 2022 she received the Charpak-Ritz Prize by the French and Swiss Physical Societies. In 2025, she became a member of the U.S. National Academy of Sciences.