文|《中国科学报》记者李思辉 实习生 王悟诚 1939年，苏联物理学家阿尔卡季·米格达尔提出一个物理学的基础理论预言——"米格达尔效应"，该效 应被认为是突破轻暗物质探测能量阈值的关键理论路径。 然而，该理论预言提出后的80多年间，中性粒子碰撞过程中是否存在米格达尔效应一直未被证实。近 日，由中国科学院大学联合广西大学、华中师范大学等单位组成的合作科研团队，首次在实验中直接观 测到了这一物理现象。相关成果发表于Nature。 为了"看见" "这个结果来得并不突然，但真正看到它被验证，还是非常激动。"华中师范大学教授孙向明说。 孙向明介绍，米格达尔效应是一个著名的物理理论预言。该预言认为，当中性粒子与原子核碰撞时，反 冲原子核将部分能量传递给核外电子，使电子有概率获得足够的能量脱离原子束缚，形成"共顶点"的两 条带电径迹——核反冲径迹和电子径迹。这一预言虽一直未被证实，但被很多科学家默认，很多科学研 究都建立在这一理论基础之上。 中国科学院大学教授郑阳恒、刘倩团队领衔的这项联合研究，研发了"微结构气体探测器+像素读出芯 片"超灵敏探测装置，相当于一台"照相机"，可拍摄"单原子运动释放电子的过程"。 研究人员利用 ...

Core Insights - A Chinese research team successfully observed the Migdal effect in neutron collisions, marking a significant milestone in dark matter detection, as reported in the journal Nature on January 15, 2026 [1][2][3] Group 1: Research and Development - The research team, led by the University of Chinese Academy of Sciences and involving multiple universities, developed a highly sensitive gas pixel detector, likened to an "atomic-level camera" [3][4] - The detector was initially designed for X-ray polarization detection but was adapted for observing the Migdal effect, which is crucial for detecting light dark matter [6][7] - The team conducted over 150 hours of experiments, capturing more than one million collision events, ultimately confirming six images that aligned with theoretical predictions [4][10] Group 2: Collaboration and Innovation - The project exemplified a model of "organized free exploration," allowing researchers from various institutions to collaborate effectively while pursuing their scientific interests [7][8] - The collaboration included contributions from different universities, focusing on various aspects such as software algorithms, data analysis, and experimental equipment [7][8] - The initiative also involved a talent development program, encouraging students to engage deeply in research from an early stage [7][8] Group 3: Challenges and Perseverance - The team faced numerous challenges, including harsh working conditions and technical difficulties during experiments, which required resilience and adaptability [3][4][10] - Despite setbacks, such as equipment failures and missed observational opportunities, the team maintained a positive outlook, viewing challenges as part of the scientific process [9][10] - The collaborative spirit and shared enthusiasm for discovery among team members fostered a creative environment, leading to innovative solutions and advancements in their research [9][10]

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].

Group 1 - The core achievement of the research is the first direct experimental confirmation of the Migdal effect in a neutral particle collision scenario, marking a significant step forward in the detection of light dark matter [1] - The Migdal effect, proposed by physicist Arkadi Migdal in 1939, describes how energy gained by an atomic nucleus can transfer to outer electrons, allowing them to escape the atomic binding, thus converting undetectable low-energy nuclear recoil signals into observable electronic signals [1] - The breakthrough in this research is attributed to advancements 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] Group 2 - The experimental team utilized a highly sensitive detection device, likened to a "camera" that captures the process of electron release during atomic motion, successfully "photographing" the unique trajectory formed by nuclear recoil and Migdal electrons [2] - The experiment not only validated the Migdal effect but also provided the first measurement of the ratio of the effect's cross-section to the nuclear recoil cross-section, offering crucial calibration data for international dark matter experiments [2]

Core Insights - The research team from the University of Chinese Academy of Sciences has successfully observed the Migdal effect during neutron-nucleus collisions, providing crucial experimental evidence for detecting lighter dark matter [1][3]. Group 1: Dark Matter and Migdal Effect - Dark matter constitutes approximately 85% of the total mass in the universe, yet it has only been detectable through gravitational effects, with no other methods available [3]. - The Migdal effect, proposed by physicist Arkadi Migdal in 1939, describes a quantum phenomenon where energy from a particle collision can be transferred to an outer electron of the nucleus, potentially allowing low-energy signals to be detected [3][4]. - For over 80 years, the Migdal effect in neutral particle collisions had not been experimentally confirmed, leading to skepticism regarding dark matter detection experiments relying on this theoretical framework [3][4]. Group 2: Research Methodology and Findings - The research team developed a highly sensitive detection device combining a microstructured gas detector and a pixel readout chip, functioning like a "camera" that captures the electron release process during atomic motion [3][4]. - By utilizing a compact deuterium-deuterium fusion reaction neutron source, the team was able to distinguish the Migdal effect from background noise, achieving a statistical significance exceeding five standard deviations, thus meeting the criteria for a physical discovery [4]. - The team plans to further optimize the detector's performance and expand observations of the Migdal effect across different elements, aiming to support the detection of lighter dark matter particles [5].

Core Insights - The research team from the University of Chinese Academy of Sciences, in collaboration with several universities, has directly observed the Migdal effect, a phenomenon predicted by quantum mechanics, which provides crucial support for breakthroughs in light dark matter detection [3]. Group 1: Migdal Effect - The Migdal effect, predicted in 1939 by Soviet scientist Migdal, describes how energy is transferred from a recoiling atomic nucleus to outer electrons during collisions with neutral particles [3]. - For over 80 years since the theoretical prediction, the existence of the Migdal effect in neutral particle collision processes had not been confirmed, leading to skepticism regarding dark matter detection experiments relying on this effect [3]. Group 2: Research Methodology - The research team developed a highly sensitive detection device combining a "micro-structured gas detector" and a "pixel readout chip," functioning like a "camera" that captures the process of electrons being released during single atomic movements [4]. - Using a compact deuterium-deuterium fusion reaction neutron source, the device can distinguish the unique tracks formed by nuclear recoil and Migdal electrons, successfully confirming the Migdal effect for the first time [4]. Group 3: Future Plans - The research team plans to further optimize the performance of the detector and expand observations of the Migdal effect across different elements, aiming to provide data support for the detection of lighter dark matter particles [4].

Core Viewpoint - Chinese scientists have made a significant breakthrough in dark matter detection by directly observing the "Migdal effect," confirming a quantum mechanics theory proposed over 80 years ago, which may open new avenues for dark matter research [5][9]. Group 1: Research and Development - The research team, led by professors from the University of Science and Technology of China, developed a highly sensitive detection device that can capture the "Migdal effect" [5][8]. - The device combines a micro-structured gas detector with a pixel readout chip, functioning like a "camera" that can observe the release of electrons during atomic movements [8]. - The team successfully distinguished "Migdal events" from background noise, achieving a statistical significance exceeding five standard deviations, which is a gold standard in particle physics [8]. Group 2: Implications for Dark Matter Research - The discovery of six "Migdal events" serves as a calibration tool for future light dark matter detection experiments, providing critical data to enhance detection capabilities [9]. - The research team plans to optimize the detector's performance and expand observations of the "Migdal effect" across different elements, which will support the detection of lighter dark matter particles [9]. - The findings allow for the adjustment of analysis strategies in international dark matter detection projects, potentially improving sensitivity [9].

Core Insights - The research led by the University of Chinese Academy of Sciences, in collaboration with Guangxi University and Central China Normal University, has successfully confirmed the Migdal effect in a neutral particle collision scenario, marking a significant advancement in the detection of light dark matter [1][2] - The Migdal effect, proposed by Soviet physicist Arkadi Migdal in 1939, is considered a crucial physical pathway to overcome the detection threshold for light dark matter [1] - The breakthrough in this research is attributed to the performance enhancement of the detector, specifically the gas microchannel plate pixel detector, which was adapted for ground experiments after over a decade of development [1] Research Details - The experimental team utilized a gas pixel detector developed by Guangxi University as the core component to create a highly sensitive detection device, capable of capturing the electron release process during atomic motion [2] - The experiment involved bombarding gas molecules within the detector with a neutron source, successfully capturing the unique trajectory of the resulting atomic recoil and Migdal electrons, thereby validating the Migdal effect [2] - This research not only provides critical support for breaking the detection threshold for light dark matter but also offers the first measurement of the ratio between the cross-section of the Migdal effect and the atomic recoil cross-section, serving as a key calibration reference for international dark matter experiments [2]

Core Findings - The research team led by the University of Chinese Academy of Sciences has directly observed the Migdal effect for the first time, providing crucial support for breakthroughs in light dark matter detection [1][2] - The Migdal effect, proposed by physicist Arkadi Migdal in 1939, involves energy transfer from an atomic nucleus to its outer electrons during recoil, allowing electrons to escape atomic binding [1] Research Methodology - The team developed a highly sensitive detection device combining a "micro-structured gas detector" and a "pixel readout chip," functioning like a "camera" to capture the process of electron release during single atom motion [2] - Utilizing a compact deuterium-deuterium fusion reaction neutron source, the device distinguishes the unique tracks of nuclear recoil and Migdal electrons from background interference [2] Implications and Future Directions - This achievement fills a long-standing gap in experimental verification of the Migdal effect and strengthens its theoretical foundation, showcasing the capabilities of domestic high-quality gas detection technology [2] - The research team plans to collaborate with dark matter detection experiment teams to integrate these findings into the development of next-generation detectors, emphasizing the importance of dark matter in understanding the universe's origins and evolution [2][3]

Core Viewpoint - The article discusses the first direct observation of the Migdal effect, a significant breakthrough in physics that could aid in the exploration of light dark matter and address a long-standing theoretical gap in the field [3][4]. Group 1: Research Findings - The research team successfully observed the Migdal effect by bombarding gas molecules in a detector with neutrons, distinguishing the "co-vertex" images of simultaneous nuclear and electronic events from complex background noise [6]. - This discovery marks the end of an 80-year wait in the physics community for direct evidence of the Migdal effect, solidifying its theoretical foundation [4][10]. Group 2: Implications - The direct observation of the Migdal effect fills a long-existing experimental validation gap and brings humanity closer to unraveling the mysteries of the universe, particularly regarding dark matter [10].