通过熊猫X-4T实验中的相干弹性中微子-原子核散射首次探测到太阳⁸B中微子。

First Indication of Solar ^{8}B Neutrinos through Coherent Elastic Neutrino-Nucleus Scattering in PandaX-4T.

作者信息

Bo Zihao, Chen Wei, Chen Xun, Chen Yunhua, Cheng Zhaokan, Cui Xiangyi, Fan Yingjie, Fang Deqing, Gao Zhixing, Geng Lisheng, Giboni Karl, Guo Xunan, Guo Xuyuan, Guo Zichao, Han Chencheng, Han Ke, He Changda, He Jinrong, Huang Di, Huang Houqi, Huang Junting, Hou Ruquan, Hou Yu, Ji Xiangdong, Ji Xiangpan, Ju Yonglin, Li Chenxiang, Li Jiafu, Li Mingchuan, Li Shuaijie, Li Tao, Li Zhiyuan, Lin Qing, Liu Jianglai, Lu Congcong, Lu Xiaoying, Luo Lingyin, Luo Yunyang, Ma Wenbo, Ma Yugang, Mao Yajun, Meng Yue, Ning Xuyang, Pang Binyu, Qi Ningchun, Qian Zhicheng, Ren Xiangxiang, Shan Dong, Shang Xiaofeng, Shao Xiyuan, Shen Guofang, Shen Manbin, Sun Wenliang, Tao Yi, Wang Anqing, Wang Guanbo, Wang Hao, Wang Jiamin, Wang Lei, Wang Meng, Wang Qiuhong, Wang Shaobo, Wang Siguang, Wang Wei, Wang Xiuli, Wang Xu, Wang Zhou, Wei Yuehuan, Wu Weihao, Wu Yuan, Xiao Mengjiao, Xiao Xiang, Xiong Kaizhi, Xu Yifan, Yao Shunyu, Yan Binbin, Yan Xiyu, Yang Yong, Ye Peihua, Yu Chunxu, Yuan Ying, Yuan Zhe, Yun Youhui, Zeng Xinning, Zhang Minzhen, Zhang Peng, Zhang Shibo, Zhang Shu, Zhang Tao, Zhang Wei, Zhang Yang, Zhang Yingxin, Zhang Yuanyuan, Zhao Li, Zhou Jifang, Zhou Jiaxu, Zhou Jiayi, Zhou Ning, Zhou Xiaopeng, Zhou Yubo, Zhou Zhizhen

机构信息

School of Physics and Astronomy, Shanghai Jiao Tong University, Key Laboratory for Particle Astrophysics and Cosmology (MoE), Shanghai Key Laboratory for Particle Physics and Cosmology, Shanghai 200240, China.

New Cornerstone Science Laboratory, Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 201210, China.

出版信息

Phys Rev Lett. 2024 Nov 8;133(19):191001. doi: 10.1103/PhysRevLett.133.191001.

DOI:10.1103/PhysRevLett.133.191001

PMID:39576898

Abstract

The PandaX-4T liquid xenon detector at the China Jinping Underground Laboratory is used to measure the solar ^{8}B neutrino flux by detecting neutrinos through coherent scattering with xenon nuclei. Data samples requiring the coincidence of scintillation and ionization signals (paired), as well as unpaired ionization-only signals (US2), are selected with energy threshold of approximately 1.1 keV (0.33 keV) nuclear recoil energy. Combining the commissioning run and the first science run of PandaX-4T, a total exposure of 1.20 and 1.04 tonne·year are collected for the paired and US2, respectively. After unblinding, 3 and 332 events are observed with an expectation of 2.8±0.5 and 251±32 background events, for the paired and US2 data, respectively. A combined analysis yields a best-fit ^{8}B neutrino signal of 3.5 (75) events from the paired (US2) data sample, with ∼37% uncertainty, and the background-only hypothesis is disfavored at 2.64σ significance. This gives a solar ^{8}B neutrino flux of (8.4±3.1)×10^{6} cm^{-2} s^{-1}, consistent with the standard solar model prediction. It is also the first indication of solar ^{8}B neutrino "fog" in a dark matter direct detection experiment.

摘要

位于中国锦屏地下实验室的熊猫X-4T液氙探测器，通过探测中微子与氙核的相干散射来测量太阳⁸B中微子通量。选择闪烁信号和电离信号符合的（成对）数据样本，以及仅电离的非成对信号（US2），其核反冲能量的能量阈值约为1.1 keV（0.33 keV）。结合熊猫X-4T的调试运行和首次科学运行，成对数据和US2数据分别收集了1.20和1.04吨·年的总曝光量。解盲后，成对数据和US2数据分别观测到3个和332个事例，预期的本底事例分别为2.8±0.5个和251±32个。联合分析给出了成对（US2）数据样本中⁸B中微子信号的最佳拟合值为3.5（75）个事例，不确定度约为37%，仅本底假设在2.64σ显著性水平下被否定。这给出了太阳⁸B中微子通量为(8.4±3.1)×10⁶ cm⁻² s⁻¹，与标准太阳模型预测一致。这也是在暗物质直接探测实验中首次出现太阳⁸B中微子“雾”的迹象。