Measurement of two-neutrino double electron capture half-life of 124Xe with PandaX-4T

作者：Zihao Bo, Wei Chen, Xun Chen, Yunhua Chen, Zhaokan Cheng, Xiangyi Cui, Yingjie Fan, Deqing Fang, Zhixing Gao, Li‐Sheng Geng, Karl Giboni, Xunan Guo, Xuyuan Guo, Zichao Guo, Chencheng Han, K. Han, Changda He, Jinrong He, Di Huang, Houqi Huang, J. Huang, Ruquan Hou, Yu Hou, Xiangdong Ji, Xiangpan Ji, Yonglin Ju, Chenxiang Li, Jiafu Li, Mingchuan Li, Shuaijie Li, Tao Li, Zhiyuan Li, Q. Lin, Jianglai Liu, Congcong Lu, Xiaoying Lu, Lingyin Luo, Yunyang Luo, Wenbo Ma, Yugang Ma, Yajun Mao, Yue Meng, Xuyang Ning, Binyu Pang, Ningchun Qi, Zhicheng Qian, Xiangxiang Ren, Dong Shan, Xiaofeng Shang, Xiyuan Shao, Guofang Shen, Manbin Shen, Wenliang Sun, Yi Tao, Anqing Wang, Guanbo Wang, Hao Wang, Jiamin Wang, Lei Wang, Meng Wang, Qiuhong Wang, Shaobo Wang, Siguang Wang, W. Wang, Xiuli Wang, Xu Wang, Zhou Wang, Y. Wei, Weihao Wu, Wu Yuan, Mengjiao Xiao, Xiang Xiao, Kaizhi Xiong, Yifan Xu, Shunyu Yao, Binbin Yan, Xiyu Yan, Yong Yang, Peihua Ye, Chunxu Yu, Ying Yuan, Zhe Yuan, Youhui Yun, Xinning Zeng, Minzhen Zhang, Peng Zhang, Shibo Zhang, Shu Zhang, Tao Zhang, Wei Zhang, Yang Zhang, Yingxin Zhang, Yuanyuan Zhang, Li Zhao, Jifang Zhou, Jiaxu Zhou, Jiayi Zhou, N. Zhou, Xiaopeng Zhou, Yubo Zhou, Zhizhen Zhou · 发表于：Journal of High Energy Physics · 年份：2025 · DOI：10.1007/jhep05(2025)119 · 被引用次数：6 · 研究领域：Neutrino Physics Research、Dark Matter and Cosmic Phenomena、Particle physics theoretical and experimental studies

A bstract Detailed studies of two-neutrino double electron capture (2 ν DEC) is a crucial step towards searching for the neutrinoless mode to explore the Majorana nature of neutrinos. We have measured precisely the half-life of the 2 ν DEC process in 124 Xe, utilizing a total exposure of 1.73 tonne year from the commissioning run and the first science run of the PandaX-4T experiment. A time-dependent background model in the $$ \mathcal{O} $$ O (10 keV) energy is constructed for the first time in PandaX-4T data. With an unbinned maximum likelihood fit, we determine the half-life of the 2 ν DEC process to be (1.03 ± 0.15 stat ± 0.08 sys ) × 10 22 yr. Furthermore, we have evaluated the capture fraction for both electrons captured from the K shell ( KK ) to be (65 ± 5)%, which aligns with the 124 Xe nuclear model calculations within 1.8 σ .