Nat Commun. 2025 Jan 15;16(1):681. doi: 10.1038/s41467-024-55042-y.
The beta decay of the lightest charmed baryon provides unique insights into the fundamental mechanism of strong and electro-weak interactions, serving as a testbed for investigating non-perturbative quantum chromodynamics and constraining the Cabibbo-Kobayashi-Maskawa (CKM) matrix parameters. This article presents the first observation of the Cabibbo-suppressed decay , utilizing 4.5 fb of electron-positron annihilation data collected with the BESIII detector. A novel Graph Neural Network based technique effectively separates signals from dominant backgrounds, notably , achieving a statistical significance exceeding 10σ. The absolute branching fraction is measured to be (3.57 ± 0.34 ± 0.14) × 10. For the first time, the CKM matrix element is extracted via a charmed baryon decay as . This work highlights a new approach to further understand fundamental interactions in the charmed baryon sector, and showcases the power of modern machine learning techniques in experimental high-energy physics.
最轻的含粲重子的β衰变，为深入了解强相互作用和电弱相互作用的基本机制提供了独特视角，可作为研究非微扰量子色动力学以及限制卡比博-小林-益川（CKM）矩阵参数的试验平台。本文利用北京谱仪III（BESIII）探测器收集的4.5飞靶电子-正电子湮灭数据，首次观测到卡比博压低衰变 。一种基于图神经网络的新技术有效地将信号与主要本底（特别是 ）区分开来，实现了超过10σ的统计显著性。测得绝对分支比为(3.57 ± 0.34 ± 0.14)×10 。首次通过含粲重子衰变提取出CKM矩阵元 为 。这项工作突出了一种进一步理解含粲重子领域基本相互作用的新方法，并展示了现代机器学习技术在实验高能物理中的强大作用。
