近日，中国科学院上海光学精密机械研究所王文涛团队研究了超短高强度激光产生μ介子的原理证明。相关论文发表在2025年5月6日出版的《自然—物理学》杂志上。
μ介子在基础物理学和应用物理学中都起着至关重要的作用。传统上，它们是由宇宙射线或质子加速器产生的。随着能够将电子加速到千兆电子伏特能量的超短高强度激光器的出现，μ介子也可以在激光实验室中生产。研究组报告了μ介子产生的原理证明实验。他们用超短、高强度的激光脉冲将电子束加速到千兆电子伏特能量，并将电子束穿过产生μ子的铅转换器靶。还通过测量μ介子的寿命证实了μ介子信号。
课题组研究了μ子产生的光产生、电产生和Bethe-Heitler过程，以及随后用Geant4模拟进行的检测。结果表明，主要贡献来自光生产和电生产。研究组估计，在转换器靶中，每个入射电子的μ子产量可达0.01μ子。这种激光驱动的μ介子源具有紧凑、超短脉冲和高通量的特点。此外，在小型激光实验室中实施该技术相对简单，大大减少了μ介子X射线元素分析或μ介子自旋光谱学等领域的研究障碍。
附：英文原文
Title: Proof-of-principle demonstration of muon production with an ultrashort high-intensity laser
Author: Zhang, Feng, Deng, Li, Ge, Yanjie, Wen, Jiaxing, Cui, Bo, Feng, Ke, Wang, Hao, Wu, Chen, Pan, Ziwen, Liu, Hongjie, Deng, Zhigang, Zhang, Zongxin, Chen, Liangwen, Yan, Duo, Shan, Lianqiang, Yuan, Zongqiang, Tian, Chao, Qian, Jiayi, Zhu, Jiacheng, Xu, Yi, Yu, Yuhong, Zhang, Xueheng, Yang, Lei, Zhou, Weimin, Gu, Yuqiu, Wang, Wentao, Leng, Yuxin, Sun, Zhiyu, Li, Ruxin
Issue&Volume: 2025-05-06
Abstract: Muons play a crucial role in both fundamental and applied physics. Traditionally, they have been generated from cosmic rays or with proton accelerators. With the advent of ultrashort high-intensity lasers capable of accelerating electrons to gigaelectronvolt energies, muons can also be produced in laser laboratories. Here we report a proof-of-principle experiment of muon production. We accelerated an electron beam to gigaelectronvolt energies with an ultrashort, high-intensity laser pulse and passed the beam through a lead converter target in which muons were generated. We confirmed the muon signal by measuring its lifetime. We investigated the photo-production, electro-production and Bethe–Heitler processes underlying muon generation and their subsequent detection with Geant4 simulations. The results show that the dominant contribution stems from photo-production and electro-production. We estimate that a muon yield of up to 0.01 muon per incoming electron could be achieved in the converter target. This laser-driven muon source features compact, ultrashort pulses and high flux. Moreover, its implementation in a small laser laboratory is relatively straightforward, which dramatically reduces barriers for research in areas such as muonic X-ray elemental analysis or muon spin spectroscopy.
DOI: 10.1038/s41567-025-02872-2
Source: https://www.nature.com/articles/s41567-025-02872-2