近日，德国马克斯-普朗克物理研究所C. Buck团队研究了相干弹性反中微子-核散射的直接观测。这一研究成果发表在2025年7月30日出版的《自然》杂志上。

中微子是一种基本粒子，与物质的相互作用非常微弱。因此，中微子实验通常规模很大，实验质量在数吨范围内。中微子在原子核上的相干弹性散射的无阈值相互作用大大提高了相互作用率，有望实现更小的探测器。对该过程的研究有助于深入了解超越粒子物理标准模型的物理学。

CONUS+实验旨在用核反应堆中产生的低能中微子率先探测在完全相干状态下的弹性中微子-核散射。为此，研究组开发了基于极低能量阈值的高纯度锗晶体的半导体探测器。他们报道了在瑞士莱布施塔特核电站进行的CONUS+实验中，首次观测到一个统计显著性为3.7σ的中微子信号。

在反应堆运行的119天内，研究组共测量到（395±106）个中微子，而根据标准物理模型计算得出的预测值为（347±59）次事件。随着精度的提高，未来有望取得重大发现。因此，CONUS+的结果结合该相互作用通道的其他测量数据，有望揭开中微子物理学新时代的序幕。

附：英文原文

Title: Direct observation of coherent elastic antineutrino–nucleus scattering

Author: Ackermann, N., Bonet, H., Bonhomme, A., Buck, C., Flber, K., Hakenmller, J., Hempfling, J., Heusser, G., Lindner, M., Maneschg, W., Ni, K., Rank, M., Rink, T., Snchez Garca, E., Stalder, I., Strecker, H., Wink, R., Woenckhaus, J.

Issue&Volume: 2025-07-30

Abstract: Neutrinos are elementary particles that interact only very weakly with matter. Neutrino experiments are, therefore, usually big, with masses in the multi-tonne range. The thresholdless interaction of coherent elastic scattering of neutrinos on atomic nuclei leads to greatly enhanced interaction rates, which allows for much smaller detectors. The study of this process gives insights into physics beyond the Standard Model of particle physics. The CONUS+ experiment1 was designed to first detect elastic neutrino–nucleus scattering in the fully coherent regime with low-energy neutrinos produced in nuclear reactors. For this purpose, semiconductor detectors based on high-purity germanium crystals with extremely low-energy thresholds were developed2. Here we report the first observation of a neutrino signal with a statistical significance of 3.7σ from the CONUS+ experiment, operated at the nuclear power plant in Leibstadt, Switzerland. In 119days of reactor operation (395±106) neutrinos were measured compared with a predicted number from calculations assuming Standard Model physics of (347±59) events. With increased precision, there is potential for fundamental discoveries in the future. The CONUS+ results in combination with other measurements of this interaction channel might therefore mark a starting point for a new era in neutrino physics.

DOI: 10.1038/s41586-025-09322-2

Source: https://www.nature.com/articles/s41586-025-09322-2