Measurements of All-Particle Energy Spectrum and Mean Logarithmic Mass of Cosmic Rays from 0.3 to 30 PeV with LHAASO-KM2A

作者：Z. Cao, F. Aharonian, Axikegu, Y. Bai, Y. W. Bao, D. Bastieri, X. J. Bi, Y. J. Bi, W. Bian, A. V. Bukevich, Qiku Cao, Wenjing Cao, Zhe Cao, J. Chang, Jin Chang, A. M. Chen, E. S. Chen, H. X. Chen, Liang Chen, Lin CHEN, Long Chen, M. J. Chen, M. L. Chen, Q. H. Chen, Shaw H. Chen, Shaw H. Chen, S. Z. Chen, T. L. Chen, Yuyi Chen, Ning Cheng, Yaodong Cheng, Maxwell Cui, S. W. Cui, Xiaohong Cui, Y. D. Cui, B. Z. Dai, H. L. Dai, Zi-Gao Dai, Danzengluobu Danzengluobu, X. Q. Dong, K. K. Duan, J. H. Fan, Yi-Zhong Fan, Jun Fang, J. H. Fang, Kun Fang, C. Feng, H. Feng, Lei Feng, S. H. Feng, X. T. Feng, Y. L. Feng, Y. L. Feng, S. Gabici, Bo Gao, C. D. Gao, Qi Gao, W. Gao, W. K. Gao, M. M. Ge, Li‐Sheng Geng, Gwenael Giacinti, G. Gong, Q. B. Gou, M. H. Gu, Fulai Guo, X. L. Guo, Y. Q. Guo, Y. Y. Guo, Y. A. Han, M. Hasan, X. B. He, H. N. He, Jiafa He, Y. He, Y. K. Hor, B. W. Hou, C. Hou, X. T. Hou, H. B. Hu, Qiang Hu, S. C. Hu, D. Huang, T. Q. Huang, W. J. Huang, X. T. Huang, X. Y. Huang, Yuanyuan Huang, Xiangdong Ji, H. Y. Jia, K. Jia, K. Jiang, X. W. Jiang, Z. J. Jiang, M. Jin, M.M Kang, I. Karpikov, D. Kuleshov, K. Kurinov, Bing Li, C. M. Li, Cheng Li, Cong Li, Di Li, Fan Li, H. B. Li, Haiying Li, Jian Li, Jie Li, K. Li, S. D. Li, W. L. Li, W. L. Li, X. R. Li, Xin Li, Yunyun Li, Zhe Li, Zhuo Li, En‐Wei Liang, Liang Yu, S. J. Lin, B. Liu, C. Liu, Desheng Liu, Hao Liu, H. D. Liu, H. D. Liu, Jianglai Liu, J. Y. Liu, M. Y. Liu, R. Y. Liu, S. M. Liu, Wei Liu, Ye Liu, Y. N. Liu, Qiuyi Luo, Y. Luo, H. K. Lv, Bingjie Ma, Linwei Ma, Xinrui Ma, J. R. Mao, Z. Min, W. Mitthumsiri, Hui-Jun Mu, Y. C. Nan, A. Neronov, Z. W. Ou, P. Pattarakijwanich, Z. Y. Pei, J. C. Qi, M. Qi, Bing-Qiang Qiao, Jiajun Qin, A. Raza, D. Ruffolo, A. Sáiz, M. Saeed, D. Semikoz, L. Shao, O. Shchegolev, X. D. Sheng, Fengchun Shu, H. C. Song, Yu. V. Stenkin, V. Stepanov, Yang Su, D. X. Sun, Q. N. Sun, X. N. Sun, Z. B. Sun, J. Takata, P. H. T. Tam, Qi-jie Tang, R. Tang, Z. Tang, W. W. Tian, C. Wang, Chuxuan Wang, G. W. Wang, H. G. Wang, H.H Wang, J. C. Wang, Kai Wang, Kai Wang, L. P. Wang, L. Y. Wang, P.H Wang, Ruikang K. Wang, Wei Wang, Xiang-Gao Wang, X. Wang, Y. Wang, Y. D. Wang, Yingjie Wang, Zining Wang, Z. X. Wang, Z. Wang, Zheng Wang, Da-Ming Wei, Jun-Jie Wei, Yifan Wei, Tao Wen, C. Y. Wu, H. R. Wu, Q. W. Wu, Yongcheng Wu, X. F. Wu, Yi-Yen Wu, Shao-Qiang Xi, J. Xia, G. M. Xiang, D. X. Xiao, G. Xiao, Y. Xin, Y. Xing, D. R. Xiong, Z. Xiong, D. L. Xu, Rui Xu, Renxin Xu, W. L. Xu, L. Xue, Dahai Yan, J. Z. Yan, T. Yan, J. Y. Yang, C. Y. Yang, Fang Yang, Fang Yang, Lili Yang, Min Yang, Ruizhi Yang, W. X. Yang, Yuhua Yao, Z. G. Yao, L. Q. Yin, N. Yin, X. H. You, Z. Y. You, Y. H. Yu, Qiang Yuan, H. Yue, Houdun Zeng, T. X. Zeng, W. Zeng, M. Zha, B. B. Zhang, Fan Zhang, H. Zhang, H. Y. Zhang, H. Y. Zhang, J. L. Zhang, Li Zhang, P. F. Zhang, S. B. Zhang, R. Zhang, S. B. Zhang, X. Zhang, Siqi Zhang, X. Zhang, X. P. Zhang, Y. F. Zhang, Yi Zhang, Yong Zhang, Bing Zhao, J. Zhao, Linlin Zhao, Lei Zhao, S. P. Zhao, X. H. Zhao, F. Zheng, W. J. Zhong, Bo Zhou, H. Zhou, J. N. Zhou, Mingyue Zhou, Ping Zhou, Rong Zhou, X. X. Zhou, X. X. Zhou, B. Y. Zhu, C. G. Zhu, F. R. Zhu, H. Zhu, K. J. Zhu, Y. C. Zou, Xueman Zuo · 发表于：Physical Review Letters · 年份：2024 · DOI：10.1103/physrevlett.132.131002 · 被引用次数：52 · 研究领域：Dark Matter and Cosmic Phenomena、Radiation Therapy and Dosimetry、Calibration and Measurement Techniques

We present the measurements of all-particle energy spectrum and mean logarithmic mass of cosmic rays in the energy range of 0.3-30 PeV using data collected from LHAASO-KM2A between September 2021 and December 2022, which is based on a nearly composition-independent energy reconstruction method, achieving unprecedented accuracy. Our analysis reveals the position of the knee at 3.67±0.05±0.15 PeV. Below the knee, the spectral index is found to be -2.7413±0.0004±0.0050, while above the knee, it is -3.128±0.005±0.027, with the sharpness of the transition measured with a statistical error of 2%. The mean logarithmic mass of cosmic rays is almost heavier than helium in the whole measured energy range. It decreases from 1.7 at 0.3 PeV to 1.3 at 3 PeV, representing a 24% decline following a power law with an index of -0.1200±0.0003±0.0341. This is equivalent to an increase in abundance of light components. Above the knee, the mean logarithmic mass exhibits a power law trend towards heavier components, which is reversal to the behavior observed in the all-particle energy spectrum. Additionally, the knee position and the change in power-law index are approximately the same. These findings suggest that the knee observed in the all-particle spectrum corresponds to the knee of the light component, rather than the medium-heavy components.