【人民日报】我国科研团队首次证实米格达尔效应

Core Insights - The article discusses a significant scientific breakthrough published in the journal "Nature," where researchers from the University of Chinese Academy of Sciences, along with Guangxi University and Central China Normal University, have experimentally confirmed the Migdal effect in a neutral particle collision scenario, marking a substantial step forward in the detection of light dark matter [1][2]. Group 1: Research Findings - The Migdal effect, proposed by Soviet physicist Arkadi Migdal in 1939, describes how an atomic nucleus gaining energy can transfer some of that energy to its outer electrons, allowing them to escape the atomic binding and create observable charged tracks [1]. - For over 80 years, the Migdal effect in neutral particle collision scenarios remained unverified due to the challenges in detecting the extremely weak electronic signals and unique tracks produced during the process [1]. - The recent research achievement was made possible by breakthroughs in detector performance, specifically a gas pixel detector developed by Guangxi University, which took over 10 years to create and was completed in 2023 [1][2]. Group 2: Experimental Methodology - The experimental team utilized a highly sensitive detection device, likened to a "camera" capable of capturing the process of electron release during single atomic movements, to validate the Migdal effect [2]. - The setup involved bombarding gas molecules within the detector with a neutron source, resulting in atomic recoil and the generation of Migdal electrons, successfully capturing the unique tracks formed by their interaction [2]. - The experiment also measured the ratio of the cross-section of the Migdal effect to that of atomic recoil, providing crucial calibration data for international dark matter experiments [2].